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

<passage>:
It's my first go at delivering a baby by caesarean section – and the foetal head is impacted, jammed in its mother's pelvis. To be honest I'm struggling. others are seized upon immediately. A proper study of the clinical effectiveness of the Tydeman tube will necessarily involve women giving birth. Assessing the value of Debra as a simulator didn't require human subjects and the team has already conducted such a study. Thirty obstetricians, from three NHS maternity units and with varying levels of experience, took part. They all received a brief explanation of how Debra works, and were then asked to try a timed removal of the foetal head at three different levels of difficulty. Overall, 87 per cent reported that the simulator offered a realistic experience of dealing with an impacted head, and 93 per cent thought it would be valuable as a training device. but with a good outcome. Although the Tydeman tube is still in gestation, Desperate Debra herself is now thriving. To understand the desperation of Debra and how the Tydeman tube might help to relieve it requires a brief foray into basic obstetric knowhow.  Evolution has endowed us with heads proportionally so large that even when labour runs according to plan, the delivery process involves a bit of a squeeze. For the baby's head to get stuck on the way out may not be usual, but it's by no means a rarity. The standard response is to perform a caesarean section. Every year some 160,000 babies are born in the UK this way, with almost two thirds of them classified as emergencies. One audit has suggested that roughly 8,000 babies get stuck and have to be delivered by caesarean at a stage when their mothers are fully dilated. "Some of the babies will be so close to coming out by the normal route," says Tydeman, "that it's then difficult to get them back up and remove them through the hole in the woman's tummy." Which women are most at risk of this setback seems to be largely unpredictable. "We just observe that it happens… It's been discussed in the medical literature since the 1940s, but until 10 years ago, and throughout my training and most of my life as a consultant, it wasn't really talked about." Considering the universality of childbirth, impaction and the best way of dealing with it are topics that seem to have gone remarkably unstudied. "There are strong opinions about why it happens and what to do, but very little research evidence," says Tydeman, adding that many of these opinions are contradictory. In a protracted birth that's destined to end with a caesarean, the longer the labour is allowed to go on before the obstetrician decides to intervene, the greater the likelihood that the baby's head will become impacted. However, concern over the rising number of babies born by caesarean has made doctors more wary of doing them – one consequence of which is that medical staff may allow a difficult birth to continue for longer before they resort to surgery. This could be boosting the frequency of impaction. But, again, no one is certain. When obstetricians doing planned caesareans slice open a mother's womb, what they usually see is the baby's head. By slipping a hand round and below it they can easily guide the baby out. "When you do a caesarean for an impacted baby," says Tydeman, "you make the incision in the same place, but what you might come across is a shoulder because the baby's so much further down [the birth canal]." As I'd discovered for myself, sliding a hand around the baby's head is then far more difficult. "It makes your fingers hurt," says Tydeman. "It makes your pulse rate go up to about 200, and you break out in a sweat because know you've only got about five or 10 minutes before there are serious consequences. The clock is ticking." If a baby's head is jammed down in the mother's pelvic region, common sense suggests that it might help if a second person gives a gentle backward push on the area of its head visible through the mother's dilated cervix. "In our unit," says Tydeman, "when the woman is fully dilated and you'd expect the baby to come out normally [but it doesn't]… a registrar will be asking for a push-up about one in five times." Although registrars are doctors still in training, they're nonetheless experienced One of the treatments of choice in that era was, naturally, acupuncture. But how to teach tyro-acupuncturists where to place the needles? Simple. A life-size bronze statue dotted with small holes indicated the points of insertion. And how then to test the students' grasp of their subject? If the statute was hollow, filled with liquid and given an outer coating of wax to mask the holes, a correct needle insertion would be followed by a leak. Given the universality of childbirth it's no surprise that, then as now, the womb turns out to be the most simulated of our organs. For the benefit of 18th-century midwives and doctors-in-training, the Bologna surgeon Giovanni Antonio Galli devised a birthing simulator comprising a glass uterus supported by an artificial pelvis and containing a flexible foetus. Trainees had to deliver the baby while wearing a blindfold. Only the tutor could witness the fumbling of their hands. As the material for a convincing simulation, glass clearly has its drawbacks. But another 18th-century contraption used a pink cloth-covered mannequin comprising a female torso complete with genitalia, a set of implantable foetuses of various ages, and even – a real Although tests carried out with the Debra prototype showed that the tube would work as intended, Tydeman and his colleagues then faced what he calls a kind of medical catch-22. "We had the tube finished about three years ago… but we were more interested in trying to save lives than selling a product. We thought that the right thing to do before commercialising it was to be sure we'd got the best design." They tried it on a dozen or so women in labour, and concluded that it did what it supposed to. But they held off trying to market it because they wanted to do more extensive, more rigorous clinical studies. This presented a problem. "If you've applied for research money," says Tydeman, "but you've already got what seems to be a commercially viable design, potential funders are going to say that the company aiming to sell it should pay for the work." On the other hand, commercial interest is easier to drum up if you've already got evidence that a device is safe and effective. That said, the team didn't want to leave the tube sitting on the shelf. So they eventually decided to go ahead and find a commercial partner willing to manufacture and market it. They have now identified one, and are fairly confident it will soon be in production. With sufficient users it should then be possible to compile factual – as opposed to anecdotal – evidence of benefit. Not ideal, Tydeman concedes, but the best they can do at present. So how valuable in training medical staff is a simulator like this? Very, according to Annette Briley. Imagine it's the middle of the night and an unplanned emergency caesarean is required: "Some poor junior doctor might find himself trying to manage it on his own." To have practised the knack of extracting a firmly impacted baby from a simulator is lot better than first honing your skill on a real woman.

<question>:
What percentage of cesarean births in the UK every year are classified as emergencies?

<options>:
A Nearly one half
B Nearly two thirds
C Nearly one quarter
D Nearly three quarters

<answer>:

B