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.
One example is below.
Q: 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
A: B
Rationale: 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: Thick dust rose and a large building collapsed. This was the scene in Zhu Zhou,Hunan Province on May 17. Nine people were killed and 16 injured. Things were similar in the Sichuan earthquake. Thousands of people were buried in the ruins and lost their lives. What if we could have warned them? People are always _ to find a way of preventing buildings' collapse. Better materials and technology help,but they are not a solution. Just like humans,a building has its own life cycle from "birth" to "death".If we know when a building is going to collapse,we can repair it in advance or get out of it before it falls. Now,scientists at the University of Illinois have developed a material that turns red before it breaks. The invention could be used in things like climbing ropes or bridge supports. The research was led by Nancy Sottos,a professor at the university's Beckman Institute,and Douglas Davis,a graduate research assistant. The secret behind the color--changing material is a type of molecule .A molecule is a group of atoms held together by chemical bonds. Imagine you and your friends standing in a circle,holding hands. Each person stands for one atom,your hands represent the bonds,and the entire circle represents a molecule. If one person lets go of his or her hands,the molecule changes color. The research team put the molecule into a soft material. When the researchers stretched the material,it turned bright red for a few seconds before it broke into two pieces. When they repeatedly stretched and relaxed the material,without breaking it,it only turned a little red. The major problem is that light can get rid of the red color. When the team shone bright light on the molecule,the broken bond was fixed,and the color disappeared. Scientists have yet to do more research before the color--changing molecules can be used outside the lab.
Question: What does the passage mainly introduce?
Options: (A) The collapse of a large building in Zhu Zhou, Hunan Province. (B) A type of molecule that can be put into a soft material (C) A material that turns red before it breaks. (D) A way of preventing building from collapsing.
A:
C