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: Reading books has long been a way to relax.However,in this modern age of computers,the Internet,DVD movies and MP3 players,the simple act of reading a book has taken a back seat.People want something more interactive than just pages to turn.We seem to be turning away from the joy of reading a good book,but there is an answer. Audio books have been around for a long time.But most people think that audio books are just for people with eyesight problems.This is one of their uses,of course,but it is far from the full story. Audio books are in the form of either cassette tapes or CDs.The beauty of them is that the whole story is read often by well-known actors and actresses.It is like having your own play.There are many kinds of audio books,so you are sure to find one that suits your tastes.The really good thing of listening to an audio book is that you can listen to it wherever you want to. Audio books do not just tell stories--they also provide language lessons.Imagine learning to speak a number of key Japanese phrases while you do the ironing,or learning basic French while doing the housework.Audio books can be found in most big bookstores,as well as over the Internet.There are books for people of all ages,including kids.If you are a member of a local library,you will also find audio books to borrow,so you can try one and decide if you really want to buy one.
Question: In the writer's opinion,which of the following is a really good thing of audio books?
Options: (A) They can be found in most big bookstores. (B) They are much cheaper than printed books. (C) They can be listened to anywhere you like. (D) They can be borrowed from libraries.
Example Output: C

Example Input: Article: The round-the-clock availability that cell phones have brought to people's lives may be _ amily life, a new study suggests. The study, which followed more than 1300 adults over 2 years, found that those who consistently used a mobile phone through out the study period were more likely to report negative "spillover" between work and home life--and, in turn, less satisfaction with their family life. Spillover(,) actually means that the line between work and home began to become unclear. Work life may invade home life--when a parent is taking job-related calls at home, for instance--or family issues may start to take up work time. For example, a child may call Mom at work, telling her "the microwave exploded", explained Noelle Chesley, an assistant professor of society at the University of Wisconsin Milwaukee and the author of the study. The problem with cell phones seems to be they are allowing for ever more spillover between work and home. This may be especially true for working women, the study found. Among men, consistent use of mobile phones seemed not to allow more work issues to creep into family time. But for women, the spillover tended to go in both directions--being "connected" means that work cuts into home time, and family issues come into work life. Cell phones seem to be opening more lines for stressful exchange among family members. But there may be ways to control the spillover, according to Chesley. Employers, she said, should look at their policies on contacting employees after working hours to make sure their expectations are "reasonable". For their part, employees can decide that cell phones go off during family time, Chesley said.
Question: What is the main idea of this passage?
Options: (A) Cell phones offer 24-hour availability. (B) Cell phones get life and work mixed. (C) Women don't use cell phones in an effective way. (D) Men are better at dealing with family problems.
Example Output: B

Example Input: Article: When policy experts debate climate change solutions, they often talk about "a price on carbon." They are arguing about whether companies should pay when they put carbon pollution in the air. Proponents say that it's simple economics -- if it's free to pollute, you'll get a lot of pollution. Opponents claim it will raise the cost of energy that's produced from high carbon sources, like coal. But here's the secret that most people seem to be missing: There already is a price on carbon, and it's paid by the taxpayers. Carbon pollution, like every other form of pollution, has an impact on the environment. Throwing waste into a river will cause the fish to die and the people who drink the water to get sick. And when you produce carbon pollution, you get climate change -- sea level rise, stronger storms, severe droughts, damage to agriculture, and more. All of those impacts cost money. Insurance rates go up when storms get more destructive. Taxes increase when cities have to rebuild bridges and roads. Military budgets go up when droughts and population changes cause conflicts. Not to mention impacts on agriculture and health care costs. In other words, the price on carbon is what we all pay when there is no market force to limit the pollution that causes climate change. So the debate is really about who will pay that price -- the companies who are making a profit from the fossil fuels, or the taxpayers who pick up the cost now? Right now, we have private profit and public cost. It's just like if we allowed every business to throw its garbage in the street because it's too expensive to have it moved away properly. Does it add a little bit to your dinner check to require that restaurants dispose of their trash properly? Sure. But it would be more expensive for you if the city had to clean the streets of their garbage every day. So just like we put a "price on garbage" we need a "price on carbon pollution." Now, a "price on carbon pollution" can mean a lot of things. You could tax companies based on the amount of carbon pollution they produce, and return the money to taxpayers. You could put a limit on how much they can produce, thereby requiring them to invest in ways to conduct business in a less polluting way.
Question: What do the policy experts argue about carbon pollution?
Options: (A) Whether the companies should pay for it. (B) Whether taxpayers could get profit from it. (C) Who have the ability to change it. (D) How much should be paid for it.
Example Output:
A