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

<passage>:
learn the most fundamental things. Like when there's no use trying—when it's time to give up because it's hopeless.... The meteor, a pebble, a little larger than a match head, traveled through space and time since it came into being. The light from the star that died when the meteor was created fell on Earth before the first lungfish ventured from the sea. In its last instant, the meteor fell on the Moon. It was impeded by It drilled a small, neat hole through the casing of the steam turbine, have been formed by steam some time, because there's a floor of ice in all of 'em. "The idea didn't come all at once, it took a long time for me to remember that water is made out of oxygen and hydrogen. When I remembered that, of course, I remembered that it can be separated with electricity. So I built this thing. rest was promissory notes and grubstake shares. When he was broke, which was usually, he used his tractor to haul uranium ore and metallic sodium When he was flush, he would prospect for a couple of weeks. Once he followed a stampede to Yellow Crater, where he thought for a while that he had a fortune in chromium. The chromite petered out in a month and a half, and he was lucky to break even. Evans was about three hundred miles east of Williamson Town, the site of "Sure, man, I've thousands of tons of water here. It's the richest mine on the Moon!" claim." "Claim?" the first landing on the Moon. THE END reserve—plus one is five—plus sixteen days normal supply equals "What batteries?" he asked. "There're no batteries in here, the power main turbine, but by a small reciprocating engine. The steam, however, came from the same boiler. And the boiler, of course, had emptied itself into the cold darkness of space. When the meteor pierced the turbine, the water in the condenser began to boil. This boiling lowered the temperature, and the condenser demonstrated its efficiency by quickly pipe. He pulled on a knob marked "Nuclear Start/Safety Bypass." The water that he had poured into the boiler quickly turned into steam, and used. It was one day's supply if used wastefully. It was ostentatious It was an incredibly brilliant disk in a black sky. The stars next to at all, but he thought in the strictest sense that it would be morning on the Moon for another week. "Has the power crew set up the solar furnace?" he asked. The solar furnace was a rough parabola of mirrors used to focus the sun's heat on anything that it was desirable to heat. It was used mostly, from sun-up to sun-down, to supplement the nuclear power plant. "They went out about an hour ago," she answered, "I suppose that's what rate," he said. The power crew was having trouble with the solar furnace. Three of the nine banks of mirrors would not respond to the electric controls, and Nobody answered. They could all see the Moon under their feet. Small made millions of years ago, but here and there, the rim of a crater found that the light reflected from the small ray that peered into the cave door lighted the cave adequately. He tapped loose some white crystals on the cave wall with his geologist's hammer, and put them into a collector's bag. "A few mineral specimens would give us something to think about, man. These crystals," he said, "look a little like zeolites, but that can't be, zeolites need water to form, and there's no water on the Moon." He chipped a number of other crystals loose and put them in bags. One of them he found in a dark crevice had a hexagonal shape that puzzled him. One at a time, back in the tractor, he took the crystals out of the bags and analyzed them as well as he could without using a flame which would waste oxygen. The ones that looked like zeolites were zeolites, all right, or something very much like it. One of the crystals that he thought was quartz turned out to be calcite, and one of the ones that he was sure could be nothing but calcite was actually potassium nitrate. "Well, now," he said, "it's probably the largest natural crystal of potassium nitrate that anyone has ever seen. Man, it's a full inch All of these needed water to form, and their existence on the Moon puzzled him for a while. Then he opened the bag that had contained the unusual hexagonal crystals, and the puzzle resolved itself. There was nothing in the bag but a few drops of water. What he had taken to be a type of rock was ice, frozen in a niche that had never been warmed by the sun. The sun rose to the meridian slowly. It was a week after sunrise. The the crescent. The people on Earth saw the full moon set about the same to the Moon about once a month, carrying supplies in and metal and ores out. At this time he was visiting with his old friend McIlroy. "I swear, Mac," said Jones, "another season like this, and I'm going back to mining." "Oh, the money I like, but I will say that I'd have more if I didn't have to fight the union and the Lunar Trade Commission." tirade, "but it's not. The union it is that says who I can hire. The union it is that says how much I must pay, and how large a crew I need. it is that says what I'll sell it for. If I had my way, I'd charge only Commission insists on. That's from here to Earth, of course. There's no profit I could make by cutting rates the other way." the fuel to get from here to Earth as it does to get from there to here?" "What good would it do to charge fifty cents a pound?" asked McIlroy. "The nickel, man, the tons of nickel worth a dollar and a half on Earth, and not worth mining here the low-grade ores of uranium and vanadium, they need these things on Earth, but they can't get them as long as it isn't worth the carrying of them. And then, of course, there's the water pay for water." Both men fell silent for a while. Then Jones spoke again: "Have you seen our friend Evans lately? The price of chromium has gone up, and I think he could ship some of his ore from Yellow Crater at a profit." "He's out prospecting again. I don't expect to see him until sun-down." radio that won't carry beyond the horizon isn't any good, and one that will bounce messages from Earth takes up too much room." "Well, if I don't see him, you let him know about the chromium." "Anything to help another Welshman, is that the idea?" "Well, protection it is that a poor Welshman needs from all the English dawning line of light covered half of Earth, and Earth turned beneath it. "Because I say so," Cowalczk shouted, surprised at his outburst and ashamed of it. "Boiler scale," he continued, much calmer. "We've got to don't clog up." He squinted through his dark visor at the reactor building, a gray concrete structure a quarter of a mile distant. "It The vat was a light plastic container used only to decant sludge out of the solar furnace as a radiator, we can make do." "Oh, God, I suppose this means water rationing again." "You're probably right, at least until the next rocket lands in a couple PROSPECTOR FEARED LOST ON MOON the Moon in search of minerals was due two days ago, but it was oxygen runs out. by the fact that Evans is lost on the part of the Moon which is now "Well, yes," Jones answered. "I thought that it might happen that a rocket would be needed in the search." The light from Earth lighted the Moon as the Moon had never lighted Earth. The great blue globe of Earth, the only thing larger than the stars, wheeled silently in the sky. As it turned, the shadow of sunset

<question>:
What is the most precious commodity on the moon?

<options>:
A Water
B Oxygen
C Natural gas
D Chromite ore

<answer>:

A