user: 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.

Let me give you an example: 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
The answer to this example can be: B
Here is 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.

OK. solve this:
Article: Have you ever heard a news reporter talk about DNA?Reporters talk about DNA found at the scene of a crime.They talk about police finding DNA "fingerprints".Police sometimes use DNA as a clue to find out who committed the crime. DNA is a substance that makes up genes.Everything alive has genes.Plants have genes.Animals have genes.You have genes. Genes are the basic units of heredity .Heredity means all the characteristics you inherit from your parents.You get your genes from your parents.You inherit half of your genes from your mother.You inherit half of your genes from your father. Genes are a kind of code.A tree's genes tell what shape its leaves will be.A cat's genes tell what color its fur will be.Your genes tell what color your eyes will be.Your genes tell what color your hair will be.Everything about you comes from the code in your genes. Genes line up on strands called chromosomes in cells.Everything alive is made up of cells.Chromosomes are in the center,or nucleus of cells. Different parts of you are made of different kinds of cells.Your muscles are made of muscle cells.Your skin is made of skin cells.The code in your genes tells your body to make different kinds of cells.The genes in each cell tell the cell how to work.They tell the cell when to make new copies of itself. An Austrian monk named Gregor Mendel first saw inherited patterns in pea plants.He experimented with pea plants in the 1860s.One of the things,or traits  Mendel studied was what makes some pea plants tall and some short.He said that the traits must come from units of heredity passed from the parent plants.These units were later called genes. In the mid-1900s,scientists discovered that genes are made of DNA.In the 1970s,scientists learned how to change DNA with genetic engineering.Scientists also learned that problems with certain genes cause diseases.Muscular dystrophy,cystic fibrosis,and hemophilia are some genetic diseases--diseases caused by problems in genes.Today,scientists are looking for ways to cure genetic diseases by changing genes through a process called gene therapy. 
 Question: What is DNA? 
 Options: (A) DNA is a kind of gene. (B) DNA is a substance that makes up genes. (C) DNA is the basic unit of heredity. (D) DNA is a measure to protect crime.
Answer:

assistant: B