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: A programmer and an engineer are sitting next to each other on a long flight from Los Angeles to New York.The programmer leans over to the engineer and asks if he would like to play a fun game.The engineer just wants to take a nap, so he politely declines and rolls over to the window to catch a few winks. The programmer persists and explains that the game is really easy and has a lot of fun.He explains, "I ask you a question, and if you don't know the answer, you pay me $5.Then you ask me a question, and if I don't know the answer, I'll pay you $5." Again, the engineer politely refuses and tries to get to sleep. The programmer, now somewhat anxious, says, "OK, if you don't know the answer you pay me $5, and if I don't know the answer, I'll pay you $50!" This catches the engineer's attention, and he sees no end to this torment unless he plays, so he agrees to the game. The programmer asks the first question."What's the distance from the earth to the moon?'' The engineer doesn't say a word, but reaches into his wallet, pulls out a five dollar bill and hands it to the programmer.Now, it's the engineer's turn.He asks the programmer, "What goes up a hill with three legs, and comes down on four?" The programmer looks up at him with a puzzled look.He takes out his laptop computer and searches all of his references.After about an hour, he wakes the engineer and hands him $50.The engineer politely takes the $50 and turns away to try to get back to sleep.The programmer, more than a little angry, shakes the engineer and asks, "Well, so what's the answer?" Without a word, the engineer reaches into his wallet, hands the programmer $5, and turns away and goes back to sleep.
Question: What's the best title for the passage?
Options: (A) A Boring Conversation (B) A Fun Game (C) A Trick During The Flight (D) A Question Without Answer
Example Output: B

Example Input: Article: In the near future,we may be using our eyes to operate our smart-phones and tablets,even when it comes to playing popular games like Fruit Ninja. The Gaze Group has been developing eye-controlled computer technology for nearly 20 years.But those devices have been firstly designed to help those with disabilities,and are very expensive. "After a while,we figured out that probably the best way is to go for a mass-market way," says Gaze's Sune Alstrup Johansen."where everybody would have this available." Johansen and some of his colleagues have formed a new company,the Eye Tribe,which is hoping to develop the technology on a mass commercial level. The technology works with the help of the computing device toward the user's face. After making sure of the user's eye movements,the technology is then able to easily find where a person's eyes are moving,and then allow the eyes to control a cursor . "Our software can then determine the location of the eyes and know where you're looking on the screen to make sure what you're looking at,"reads an explanation on the Eye Tribe site. There has been a gradual change toward hands-free technology in recent years, particularly in the gaming world.Recently Xbox released the Kinect device,which lets users control their Xbox and play certain games using only their hands,legs and voices. But still,most of these devices have been more of a _ than a practical way to use one's hands to control a mobile device.Johansen said a replaceable filter would be a cheap,convenient way for most consumers. And even as companies like The Eye Tribe work to create such a product for the average user, making the eye-controlled technology more accessible and less expensive will have similar benefits for physically disabled users. For more articles on modern science,please CLICK here.
Question: Which of the following is the main idea of the passage?
Options: (A) An introduction of a new device. (B) An introduction of smart-phones. (C) An introduction of eye-controlling technology. (D) An introduction of a new technology for the disabled.
Example Output: C

Example Input: Article: Some people say that the best way to reduce the size of your waist is to do stomach exercise. Many people believe that when specific muscles are exercised, the fatty tissues in the immediate area are burned up. The truth is that exercise burns fat from all over the body and not from one specific area. Of course, if you reduce the fat throughout your body, you will certainly see results around your waist too. Some people believe that you need to exercise twice a week in order to keep a sufficient level of physical fitness. However, studies directed by American scientists show that unexercised muscles lose their strength very quickly. Within 48 to 72 hours, you must use the muscles again to reestablish the good physical effects. And what does that mean to you? American scientists concluded that while daily exercise is most helpful, exercising every other day or three days a week will keep a sufficient level of physical fitness. Is it true that you burn more calories running one mile than walking the same distance? The answer is no. The truth is that you use the same amount of energy whether you walk or run the mile, since in both cases you are moving the same weight the same distance. The speed does not matter. Of course, if you run rather than walk for 30 minutes, you will cover more distance, and therefore burn more calories. If your breathing doesn't return to normal within 5 minutes after you finish exercising, you have exercised too much. Five minutes or so after exercising, your breathing should be normal, your heart shouldn't be beating loudly, and you shouldn't be tired.
Question: If you want to reduce the fat around your waist, you should _ .
Options: (A) do stomach exercise (B) exercise the waist (C) exercise all the muscles of your body (D) run fast for 30 minutes
Example Output:
C