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: My son Paul got a job in a large chain of guitar stores. It was the first time for him to do such a job. The pay was based on a small salary and his sales. They offered him some training on how to get close to a customer, introduce the product and make the sale. However, he wasn't doing well. He was very _ . One morning Paul said to me, "Mum, you used to be a sales trainer. Can you tell me why I'm not doing well?" I said, "The key is that you must love the people you are selling your product to, not count the money you will make in your mind. Do what is best for them even though they are just buying something small or a cheap guitar." He promised he would try it. After some time, his sales began to increase. He became the top salesman in the store and his salary was increased. Within six months, he was one of the top ten salespeople in the whole chains of guitar stores around the country. His company held a big party to honor the top ten salespeople. New cars, great hotels and delicious dinners were the prizes. Paul was of course included. After the dinner, the boss of the company asked, "Paul, how did you make it?" Paul answered, " I don't want to tell you. You won't believe me." "Of course I'll believe you. Tell me." "I started loving the people who came in," Paul told him. The boss replied, "Okay Paul, now tell me how you REALLY make it."
Question: His mother suggested that Paul should _ .
Options: (A) always introduce the cheap guitars to customers (B) show love and respect to his customers (C) work out how much he would make before each sale (D) learn from the top ten salespeople in his company

Ex Output:
B

Ex Input:
Article: Throughout your life, you spend the most time being with or dealing with yourself, but it is exactly yourself that you have the least understanding of. When you are going upwards in life, you tend to think too highly of yourself. When you are going downhill, you tend to have too low an opinion of yourself. It's likely that you think it wise for yourself to know your place and keep yourself from lacking courage to face whatever problem you meet with, in which case your energy and creativity would remain far from enough for your age. To get a thorough understanding of oneself is to gain a correct view of oneself and be a clear-minded realistic person-knowing both one's strength and shortage. You may look forward hopefully to the future but be sure not to expect too much, for dreams can never be fully realized. You may be brave to meet challenges, but it should be clear to you where to direct your efforts. To get a thorough understanding of oneself needs self-appreciation. Whether you hold yourself as a big tree or a thin piece of grass, whether you think you are a high mountain or a small stone, you show a state of nature that has its own reason of existence. If you really admire yourself, you'll have a real sense of self-appreciation which will give you self-confidence. As soon as you gain full confidence in yourself, you'll be enabled to fight and defeat any trouble that will otherwise defeat you. To get a thorough understanding of oneself also requires that you show yourself loving concern about your health and daily life. Unless you know perfectly well when and how to do yourself a favor, you won't be confident and ready enough even to resist the attack of illness. Therefore, just do yourself a favor whenever it's needed. In time of anger, do yourself a favor by giving an exit to it in a quiet place so that you won't be hurt by the anger itself; in time of sadness, do yourself a favor by sharing it with your friends so as to change a sad mood into a cheerful one; in time of tiredness, do yourself a favor by getting a good sleep or some other relaxation. All in all, to get a thorough understanding of oneself is to get a full control one's life. Then one will find one's life full of color1, pleasure and achievement.
Question: Where does our self-confidence come from?
Options: (A) Our self-appreciation. (B) Our courage to fight. (C) Our natural existence. (D) Our strength and shortage.

Ex Output:
A

Ex Input:
Article: The year of 2014 saw smart people always busy inventing useful things, which have hepled to make the world better, smarter and a little for fun. Now, let's take a look at some of the inventions. Super banana Australian biogeneticist James Dale visited Uganda, a poor African country, in the early 2000s, where he found that 15-30 percent of children under 5 were at risk of going blind because they did not get enough Vitamin A. Dale also learned that people there love bananas. They eat three to 11 bananas a day. So he came up with the idea to plant bananas containing added nutrition in order to improve Ugandans' health. With the help of Bill Gates' foundation, Dale developed the "super banana". He added a gene to the fruit, making it rich in Vitamin A. Coaching basketball Basketball is popular worldwide, partly because you only need a hoop and a ball to play the game. But this simple game has experienced a technology makeover this year with the development of a smart-sensor basketball. The ball, called the 94Fifty Basketball, has nine sensors inside. They can tell you anything from how fast you are going to how accurate your shot angles are. With a Bluetooth chip inside, the basketball can connect to your smartphone and tell you in the voice of a coach to "snap your wrist ", or"go faster", depending on the data. The Hovercraft Thanks to the California-based company Hendo, flying past your friends on a floating board could soon become a reality. The Hovercraft has four small engines. These create a special magnetic field which produce enough force to lift the board off the ground. At the moment, the hoverboard can only float an inch off the ground for 15 minutes and must fly over a metal material. It's expensive too, at $10,000 (61,810 yuan), but the company hopes that one day the technology could be used. Wireless electricity Most of us could not bear to live without wireless Internet. We use it every day for everything from our phones to our cars. But one company wants to go a step further, by combining wireless technology with electricity. That's right, no more tangled wires and no more having to sit and hold your cell phone near a power socket in the corner of the room. WiTricity, a US company, has invented technology that can power objects up to 2.4 meters away. It uses a special plug-in coil that creates a magnetic field!
Question: Which of the following statements would James Dale agree with?
Options: (A) Children in Uganda should eat fewer bananas. (B) Vitamin A is largely found in fruits like bananas. (C) Super bananas are definitely a safe biological product. (D) people's eating habits can be used to develop new food.

Ex Output:
D