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: Thousands of taxi drivers in Shenyang, Liaoning province, reportedly blocked streets with their vehicles on Sunday in protest against unlicensed vehicles using taxi-hiring apps and apps-based car rental companies providing passenger services, including high-end cars. Although the drivers also complained about the withdrawal of the fuel subsidy by the government, their main complaint was the loss of business because of the rising number of Internet-based car services companies. On Wednesday, news reports came that Beijing transport authorities will take measures to stop the illegal "taxi business" of private cars through the newly rising Internet apps, following the footsteps of Shenyang and Nanjing.[:Z#xx#k.Com] It is not yet clear how the Shenyang city government will handle the issue and whether it will declare the services offered by market leaders such as Didi Dache, a taxi-hiring app provider backed by Tencent Holdings, and Kuaidi Dache illegal. But Shanghai transport regulators have set a rule, by banning Didi Zhuanche, or car services offered by Didi Dache in December. Such regulations will cause a setback to the car-hiring companies and investors that are waiting to cash in on the potentially booming business. Just last month, Didi Dache got $700 million in funding from global investors, including Singapore state investment company Temasek Holdings, Russian investment company DST Global and Tencent. Besides, the market is uncertain that Kuaidi Dache is about to finalize its latest round of funding after getting $800 million from global investors. Regulatory uncertainties, however, could cast a shadow on the future of the Internet-based car-hiring services, which have become popular in most of China's big cities. To be fair, these companies' business model is anything but bad. For example, Didi Zhuanche works side by side with established car rental companies to provide high-end car service mainly for businesspeople through the Internet and mobile phone apps. Every link in this business model chain has legal companies and services. Hence, it is hard to define it as illegal and ban it.
Question: Why did taxi drivers in Shenyang block the streets with their vehicles?
Options: (A) Because they wanted the government to increase their driving allowances. (B) Because they wanted to be educated how to use the taxi-hiring apps. (C) Because they wanted to make their main complaints known to the government. (D) Because they wanted to call on passengers not to hire the private cars.
Example Output: C

Example Input: Article: The first chocolate was eaten by people in South America hundreds of years ago. In those days, the people did not really eat chocolate. They used the cocoa bean to make a chocolate drink and they enjoyed it very much. Many years later, the cocoa bean was brought to other countries and people came to love the taste of chocolate. In 1824, John Cadbury opened a small shop in Britain. One of the things he sold was chocolate drink. In 1831, he opened a factory to make chocolate drink. He wanted to encourage people to drink chocolate instead of other drinks. A few years later, a man called Joseph Fry found a way to make chocolate instead of only drinking it. But at that time chocolate was very expensive and only the rich people could buy it. Later, ad more and more chocolate bars were produced and sold, it became cheaper. However, at first only plain chocolate (a kind of chocolate without milk and with very little sugar) was produced. Milk chocolate came later and this was made by adding milk to the chocolate. The first milk chocolate bar was made in Cadbury's factory in 1897. Their most famous chocolate, Cadbury's Milk Bar, was made in 1905, It has been the most popular chocolate in Britain and around the world for over 100 years. The Cadbury factory is still in Britain and the chocolate produced there is eaten all over the world. Every year, thousands of visitors visit the factory in order to see how chocolate is made.
Question: Hundreds of years ago, people first began to drink chocolate in_.
Options: (A) South Americ (B) South Africa (C) Britain (D) Australia
Example Output: A

Example Input: Article: You may not pay much attention to your daily lift ride. Many of us use a lift several times during the day without really thinking about it. But Lee Gray, PhD, of the University of North Carolina, the US, has made it his business to examine this overlooked form of public transport. He is known as the "Lift Guy". "The lift becomes this interesting social space where etiquette is sort of odd ," Gray told the BBC. "They (Lifts) are socially very interesting but often very awkward places." We walk in and usually turn around to face the door. If someone else comes in, we may have to move. And here, according to Gray, lift users unthinkingly go through a set pattern of movements. He told the BBC what he had observed. He explained that when you are the only one inside a lift, you can do whatever you want--it's your own little box. If there are two of you, you go into different corners, standing diagonally across from each other to create distance. When a third person enters, you will unconsciously form a triangle. And when there is a fourth person, it becomes a square, with someone in every corner. A fifth person is probably going to have to stand in the middle. New entrants to the lift will need to size up the situation when the doors slide open and then act decisively. Once in, for most people the rule is simple--look down, or look at their phones. Why are we so awkward in lifts? "You don't have enough space," Professor Babette Renneberg, a clinical psychologist at the Free University of Berlin, told the BBC. "Usually when we meet other people, we have about an arm's length of distance between us. And that's not possible in most lifts." In such a small, enclosed space it becomes very important to act in a way that cannot be construed as threatening or odd. "The easiest way to do this is to avoid eye contact,"she said.
Question: The main purpose of the article is to _ .
Options: (A) remind us to enjoy ourselves in the lift (B) tell us some unwritten rules of lift etiquette (C) share an interesting but awkward lift ride (D) analyze what makes people feel awkward in a lift
Example Output:
B