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.

Ex Input:
Article: Abby Subark is a mother of two from Boston. "For my kids, I'm nervous. I don't know if they'll be able to achieve their American dream." She may be right. More than hard work or education, the best way to get rich in America is to be born rich. It is the case that somebody who is in the upper third of income, poor scores, in the bottom on tests when they are in eighth grade, is more likely to go to college and finish college than a poor kid with the top scores. That's what the working persons' children are up against. The Economic Policy Institute finds it would take a poor couple with 2 children 9 or 10 generations to achieve middle class status. That's about 200 years. The hallmark of American opportunity has always been the ability to do better than your parents. But compared with similar developed countries, the United States ranks fifth out of six for so-called intergenerational mobility . If you look at the mechanisms for upward mobility that were so readily available 50 years ago, they are becoming out of reach, like plentiful factory jobs with good wages and affordable education and health care. White families are twice as likely as blacks to be upwardly mobile. For most people in America today, _ If you started in the middle-income class, about 40 to 45 percent of what you are making right now is due to the fact that your parents were in the middle-income class. The rest is up to you. But for the millions of people who find themselves below the poverty line and the millions more who are the working poor, their starting point for the American dream leaves them painfully far away from the middle class.
Question: The main idea of the passage is _ .
Options: (A) How the middle class comes about in the U.S. (B) It's hard to realize the American dream for the poor. (C) Wealth and social status depend on family background. (D) Upward mobility in America is never easy.

Ex Output:
C

Ex Input:
Article: Perhaps the most extraordinary building put up in the nineteenth century was the Crystal Palace which was built in Hyde Park for the Great Exhibition of 1851. The Crystal Palace was different from all the other buildings in the world, for it was made of iron and glass. It was one of the biggest buildings of all the time and a lot of people from many countries came to see it. Plenty of goods were sent to the exhibition from all parts of the world. There was also a great deal of machinery on show. Though in those days, traveling was not as easy as it is today, steamboats carried thousands of visitors across the Channel from Europe. On arriving in England, they were taken to the Crystal Palace by train. There were six million visitors in all, and the money from the exhibition was used to build museums and colleges. Later the Crystal Palace was moved to the South London. It remained one of the most famous buildings in the world until it was burnt down in 1936.
Question: The Crystal Palace was built up _ .
Options: (A) in the 1950s (B) in the 1900s (C) shortly before 1851 (D) before 1951

Ex Output:
C

Ex Input:
Article: How difficult change is depends a lot on your attitude towards it and your resistance to it. Your attitude to change can make the whole transformation process much easier. Imagine change as a pair of shoes and this will help you understand change and how it works. I am sure that you have ever had a comfortable pair of shoes in your life. A pair of shoes is so comfortable that you really don't want to get rid of them. You know you need a new pair, and may even have them, but you don't want to wear them because you are comfortable with your current pair. Besides, the new pair may hurt your feet, give you blisters or be awkward to wear to start with. So, you resist the new shoes. However, you know that this new pair would be much better for your feet, and after the initial discomfort they would probably be even more comfortable, yet you still resist. Do you know I'm doing this now? I'm wearing my comfortable shoes and they feel good. They have a hole in each heel, and the sole is starting to fall off, but I'm persisting in wearing them. This describes change exactly; change of our habits, change of our thought patterns. We stick with the old patterns because they are comfortable. Yet once we get over the initial pain of the transformation, the new pattern will be comfortable and feel good until the time comes when we need another new pair of shoes.
Question: Why do people prefer old shoes to new ones?
Options: (A) They have much emotion in the old ones. (B) They are more comfortable. (C) New shoes always harm the feet. (D) They look better than the new ones.

Ex Output:
B