In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.

Example input: Article: Homework can put you in a bad mood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay.
Question: Researchers did experiments on kids in order to find out _ .
Options: (A) how they really feel when they are learning (B) whether mood affects their learning ability (C) what methods are easy for kids to learn (D) the relationship between sadness and happiness
Example output: B
Example explanation: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment. So, B is the correct answer.
Q: Article: We don't have beds in the space shuttle, but we do have sleeping bags. During the day, when we are working, we leave the bags tied to the wall, out of the way. At bedtime we untie them and take them wherever we've chosen to sleep. On most space shuttle flights everyone sleeps at the same time. No one has to stay awake to watch over the space plane: the shuttle's computers and the enginers at the Control Office do that. If anything goes wrong. The computers ring a warning bell and the engineers call us on the radio. On the space shuttle, sleep-time doesn't mean nighttime. During each ninety-minute flight around the earth, the sun "rises" and shines through our windows for about fifty minutes: then it "sets" as our flight takes us around the dark side of the Earth. To keep the sun out of our eyes, we wear black sleep masks. It is surprisingly easy to get comfortable and fall asleep in space, and we sleep differently. Some sleep upside down, some sideways, some right side up. When it's time to sleep, I take my bag, my sleep mask, and my tape player with earphones and float up to the flight platform. Then I get into the bag, and float into a sitting position just above a seat, right next to a window. Before I pull the mask down over my eyes, I relax for a while, listening to music and watching the Earth go by under me. When I'm in space I don't need as much sleep as I do on Earth Maybe that's because when I am weightless, I don't feel as tired. Or maybe it's because I'm excited to be in space and don't want to waste time sleeping.
Question: What do the shuttle people do with their sleeping bags while working?
Options: (A) Keep them where they work. (B) Leave them where they sleep. (C) Place them on the beds. (D) Fix them to the wall.
A:
D