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: Everywhere man is altering the balance of nature.He is facilitating the spread of plants and animals into new regions, sometimes deliberately, sometimes unconsciously.He is covering huge areas with new kinds of plants, or with houses, factories, slag-heaps and other products of his civilization.He exterminates some species on a large scale, but favours the multiplication of others.In brief, he has done more in five thousand years to alter the biological aspect of the planet than has nature in five million. Many of these changes which he has brought about have had unforeseen consequences.Who would have thought that the throwing away of a piece of Canadian waterweed would have caused half the waterways of Britain to be blocked for a decade, or that the provision of pot cacti for lonely settlers' wives would have led to Eastern Australian being overrun with forests of Prickly Pear? Who would have prophesied that the cutting down of forests on the Adriatic coasts, or in parts of Central Africa, could have reduced the land to a semidesert, with the very soil washed away from the bare rock? Who would have thought that improved communications would have changed history by the spreading of disease-sleeping sickness into East Africa, measles into Oceania, very possibly malaria into ancient Greece? These are spectacular examples; but examples on a smaller scale are everywhere to be found.We make a nature sanctuary for rare birds, prescribing absolute security for all species; and we may find that some common and hardy kind of bird multiplies beyond measure and ousts the rare kinds in which we were particularly interested.We see, owing to some little change brought about by civilization, the starling spread over the English country-side in hordes.We improve the yielding capacities of our cattle; and find that now they exhaust the pastures which sufficed for less exigent stock.
Question: The following examples except _ reflect man altering the balance of nature.
Options: (A) man is covering huge areas with new kinds of plants (B) man is facilitating the spread of animals into new regions. (C) man is killing some species on a large scale (D) man is getting to know the importance of keeping the balance of nature.
A:
C