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: Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity . In very cold climates, there is a constant danger of developing hypothermia , which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0degC. However, differences in persons and even the time of day can cause it to be as much as 6degC higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4degC. Below 29.4degC, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6degC. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7degC. In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7degC. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.
Question: Why can humans keep stable body temperatures in different seasons?
Options: (A) Because their bodies are unusually efficient. (B) Because they experience different climates. (C) Because they can adjust to cultural patterns and technologies. (D) Because they have internal temperature regulating systems.

Ex Output:
D

Ex Input:
Article: Outside her cottage, old Mrs. Taylor was hanging out laundry on a wire line, unaware that some children were hiding in a nearby tree watching her every move. They were determined to find out if she really was a witch. They watched nervously as she took a broomstick to sweep the dirt from her stone steps. But much to their disappointment, she didn't get on the broomstick and fly off. The old lady only looked up when her hen began to make sounds loudly --signaling that she had laid an egg in the nest on the top of the haystack. . The old lady put aside her broomstick and walked to the haystack, followed by Michael, a black cat she had rescued from a fox trap. With only three legs, it was hard for Michael to keep up with his mistress. The cat was proof for the children that only a witch would own a black cat with three legs! Crawling further along the branches, they could clearly see the haystack. Mrs. Taylor was standing on a wooden box with the new-laid egg in one hand. Placing the egg in her pocket, she readied herself to climb down. Then, without warning, the box broke under her and she crashed to the ground. The children were in horror. "Should we go and help her?" asked Mia. "What if it's a trick?" replied Patrick. "She probably knows we're here. Witches know things like that!" After thinking for a while, Julia said"Anyway, we should go and check whether she is all right." Approaching _ , they could see a wound on the old lady's forehead. She had knocked her head on a stone and was unconscious. "Go and get Dad," Mia yelled to her brothers. "Tell him about the accident." The boys didn't need another excuse to leave. They ran as fast as they could for help, hoping that Mrs. Taylor would not regain consciousness and turn the girls into frogs. Later, in the hospital, the old lady smiled her thanks. "I was so lucky that you lovely children happened to be passing when 1 fell. I must have yelled quite loudly." The children exchanged guilty glances, but were very pleased that she was not a witch after all!
Question: Mrs. Taylor stopped sweeping when _ .
Options: (A) her doorstep became very clean (B) she heard the hen making sounds loudly (C) she noticed the children in the tree (D) her cat Michael managed to get her attention

Ex Output:
B

Ex Input:
Article: When the recent research was analyzed , it was found that a lot of people wanted free pictures or free music from the Web. If it couldn't be free, then they wanted it "new" or at least at a low price. It seems that 70 percent of people aged 16 to 24 download music online but only 1 in 40 tracks are bought legally. Thus, some companies are planning to give all of their music away for free. The music will be totally free except that you will have to pay with your time by watching advertisements. This will be perfect for those who have lots of time but little money. The Web has encouraged a belief that things can be free, or at least very cheap. It seems that everyone is looking for a good deal on the Web. The desire for free objects is part of the nature of the Web because the Web is about self-service and self-service is all about being free, cheap, fast and convenient. It's interesting how words change their meaning. Stealing has now become file sharing, but it's not really stealing, is it? Free is a funny word. We all know that very little is really for free. If we go searching on the Web for free music, we know--or should know--that there are risks involved. However, it doesn't matter. We still want free things, or at least the sense that we're getting a real bargain and that at a minimum we're saving time. What can be the worst experience on the Web? A site that charges us high prices and wastes our time.
Question: What is the best title for the text?
Options: (A) The Nature of the Web (B) The Web and the Culture of " Free" (C) Stealing and File Sharing (D) What Does the Word " Free" Mean?

Ex Output:
B