Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
The forests bear the carbon Spearheaded by the non-governmental Centre for Ecology Development and Research (CEDAR) and funded by India's Department of Science and Technology, this project is about climate change. It seeks to find out how much carbon is being absorbed by the region's forests. This is achieved by taking the information collected – foliage overlay, the height of the trees, leaf area index and canopy layer, among other things – and using it to make an allometric equation. Understanding the basic mechanism of carbon sequestration and the level of human disturbance in these forests can then provide the framework for a plan that seeks to pay local people to maintain the forests. If the project can determine how much human interaction with the forest has affected the trees' ability to photosynthesise, then local people can be paid to preserve the forest. Otherwise, its ability to act as a 'carbon sink' (anything that absorbs more carbon than it releases) risks damage from overuse. Right now, the forests of Kumaon are used primarily for fodder and fuel. Traditionally, families in the area had as many as 15 or 20 cows of their own. These cows were particularly dependent on the forest leaves for fodder and bedding. The fewer leaves a tree has, the less able it is to photosynthesise properly. Today, there are far fewer cows in the area and so fodder use has come down by a multiple of four or five in the last 10 years. The market has come to Kumaon – once an isolated area – and artificial substitutes for fodder are now available to buy locally, with NGOs providing subsidies for this. But while the pressure on the forest to provide fodder has come down, the need for it to provide fuel has gone up. This is in the Himalayan foothills, after all, and it gets cold in winter. There is little central heating and so a serious amount of wood is needed for fires to heat houses and light stoves. Where extended families once lived together, with grandparents, parents and children all under one roof, now the nuclear family is becoming the norm, meaning that requirement for fuel has gone up. And if the people of Kumaon are to use the forest less, they need compensation, or they will have no fire to warm them through the winter months. Substitutes for wood are available but are unaffordable for most. So the challenge for this project mirrors the challenge faced by climate change scientists and policymakers across the world: how can you reduce fossil fuel emissions and maintain and improve carbon sinks without disrupting or destroying the lives of local people, many of whom will be those most affected by climate change? Last March, US science agency the National Oceanic and Atmospheric Administration (NOAA) released figures that showed record concentrations of carbon dioxide in the atmosphere, at over 400 parts per million (ppm). These levels are unprecedented in over a million years and have caused over one degree of warming. The level considered 'safe' – 350 ppm – was exceeded nearly three decades ago. Today's carbon concentrations represent a more than 40 per cent increase on those found in the atmosphere in the middle of the 18th century, before the beginning of the industrial revolution. Forests are an important part of this increase. They are, along with the planet's oceans, one of two major carbon sinks. Deforestation puts carbon into the atmosphere while at the same time removing that sink. "You can say that one quarter of this increase in carbon concentrations since the 18th century has been caused by deforestation," says Corinne Le Quéré, author of the Third, Fourth and Fifth Assessments of the Intergovernmental Panel on Climate Change (IPCC) and a professor of climate change science and policy at the University of East Anglia. In 2014, the IPCC found that 11 per cent of global greenhouse gas emissions were caused by forestry and other land use. Other sources claim this figure is anything up to 30 per cent. While Le Quéré points out that the effect of deforestation was more pronounced in the 18th and 19th centuries, when it was a key driver in the process of industrialisation, she emphasises the ongoing importance of forests in the fight for a better environment. "We have very big ambitions to limit climate change well below two degrees… In terms of delivering a policy to achieve this, you absolutely need to have your forest in place and you absolutely need to tackle deforestation, because you cannot reach that level of climate stabilisation without it. Reforestation and afforestation is one of the best ways to take CO2 out of the atmosphere and forests have so many additional benefits for cleaning the air, cleaning the water, and so on." To begin working out how people in the Himalayan foothills might be reimbursed for preserving the forest, Amogh Rai and his colleagues need to find out how much carbon they are actually taking in. "We don't know how much carbon these forests are sequestering," says Rai. "If you are talking about the forest as a sink for carbon, you need to figure out how much carbon this place is storing, versus how much it is producing. And for that you need to go back to the basics of forestry. You need to figure it out by laying ecological plots measuring 400 metres squared in different areas, at different altitudes and in different disturbance gradients." Once upon a time, the strong social system – the ecologically minded functioning of the rural villages extolled by Gandhi – and dependence on the forest meant the environment was preserved. Now, these things are changing fairly rapidly. The whole idea of working as a social group is getting lost and so, Rai argues, "incentives are going to play a larger role. I've had conversations with people where they've said, 'The forests are great, we want to protect them but we don't have any money.' So it's not just about giving them an incentive to protect the forest, it's that they need money to protect the forest." With the data now collected, allometric equations will determine how much carbon is sequestered in the forests. This information will then be used to put an economic value on the various plots, which will translate into payments made to local communities through the forest councils. This money could begin to pour in within the year. "I love the forest because it is a place of silence and beauty," he says. "Also, it is one of the last places of refuge from strident urbanisation. A typical city kid reaction to noise, and tempo of life, I suppose." Rai's boss at CEDAR, Rajesh Thadani, a Yale-educated forest ecologist in his forties, is equally romantic about his attachment to the forest, quoting Thoreau to me: "I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived." It's not hard to imagine both men communing with woodland spirits. During my time in Kumaon, the Paris Climate Change Conference takes place. When I ask Rajesh Thadani how CEDAR's project fits into the bigger picture, he says: "Carbon sinks are important and a good mitigation measure – but [they] would be effective only in conjunction with other measures." There is a conflict and a contradiction here: local people may be paid to preserve the forest by using it less, but using the forest less will weaken their ties to it, thus making the desire to preserve it less urgent. It's the kind of dilemma globalised industrial capitalism throws up everywhere. The system itself has wreaked havoc on the environment, but in a structure where even people in remote areas often aspire to a certain kind of lifestyle and expect to be paid for things they might once have done for free as part of the collective harmony of a community, the monetising of things like forest maintenance has come to be seen as a potential solution.

<question>:
Why is studying forests and important aspect of understanding climate change?

<options>:
A Forests consume large amounts of oxygen in the atmosphere
B Forests house a large portion of the human population
C Forests offer a great wealth of potential resources that are necessary for economic development
D Forests absorb a large amount of the carbon dioxide in the atmosphere

<answer>:

D