You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
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.

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
Solution: B
Why? 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.

New input: Article: In the US and Britain, the slogan around colleges was "Save water. Shower with a friend." Now, Wuhan University has come up with another system for the campus bathhouse. It charges students for the amount of time in a shower. Before entering the bathhouse, students pay for the amount of time they want in the shower with cash or their student ID card. The clock starts ticking the minute the tape is turned on. It pauses when a button is pressed for soap. An integrated circuit (IC) card reader at each tap shows the time. No money, no water. The benefits of the new system can be seen with the old system, which charged 1 Yuan for each person regardless of time in the shower. The university used about 320 tons of water daily under the old system, but only 160 tons now. Many students use the new system but opinions on it are divided. Some students say it is bad because bathing had become a sort of race. Many people using it for the first time are not sure how long they need to shower. Some might be embarrassed if their time is up and they're still covered in soap. They have to ask the bathhouse worker to help them buy extra time. "It's a _ in the system that you can not buy extra time on the ID card," said Ren, a freshman in Wuhan University. The university is also considering some students' suggestions that they be allowed to pay after they've finished the shower. Not surprisingly, some are complaining about losing the hour shower. But many students say the move helps them develop a water-saving sense. Without the time limits, most students tended to shower for 30 to an hour in the bathhouse. Some even used the hot water to wash their clothes. "In my experience, 10--20 minutes is enough," said Dai Zhihua, a third-year student who usually takes 8 minutes. A similar system has been installed in other universities. Shanghai Normal University introduced it at its Fengxiang Campus in September. The bathing fee there is 0.2 Yuan per minute. One male student responded by setting a record with a two-minute shower.
Question: According to the passage, which of the following is NOT true?
Options: (A) Students buy the time of their showers. (B) The clock times the student's bathing except when the bather pauses for soap. (C) If money runs out, there will be no water. (D) Having finished bathing, the student has to pay for it.
Solution:
D