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 Q]: Article: Elephants and people are in competition for space. In much of Africa, elephants are now put in national parks. Elephants suffered a serious and steady decrease in numbers in the 1970s. This was the same time when scientists were beginning to learn a great deal about elephants and their behavior. Studies through the 1980s and into the 1990s showed a lot about their sounds and methods of communication. In Kenya alone, in the 1970s and 1980s, the elephant population decreased from 170,000 to 25,000. The sharp drop in numbers was the result of poachers illegally killing elephants for their ivory. The price of ivory went from $3 a pound to $50 to $100 a pound. Africa became very attractive to poachers. Bull elephants carried the largest tusks , so they were more often killed. With males gone and older females killed by poachers as well, there were many young elephants unable to benefit from the wisdom of the older females and matriarchs, who lead the herds. Kenya took a stand, international trade in ivory was officially forbidden, and $3,000,000 worth of confiscated ivory was burned in Kenya. The following year, only 50 elephants were lost to poachers in Kenya instead of 3,000. But Kenya has the fastest growing human population in the world. People throughout Africa won't tolerate elephants eating their crops and destroying their livelihoods. In South Africa, elephants live behind the fences of national parks. In some parts of Africa, big-game hunters pay a lot of money to hunt elephants. This keeps their numbers down, and the money goes toward conservation. In Kenya, there were some attempts at birth control to keep the elephant population at manageable numbers to reduce conflicts with people. Faced with a growing human population, elephants are losing the battle for space. It's unlikely, though, that they will become extinct. They will live in natural parks that bring tourists to Africa as well as India and other parts of Asia. The money from tourism will help elephants to survive.
Question: Bull elephants were at higher risk of being killed because _ .
Options: (A) they were the leaders of the herds (B) they possessed bigger ivory (C) they were of smaller size (D) they ran slowly
[EX A]: B

[EX Q]: Article: Testing new drugs for safety and effectiveness is a costly process in the United States. It also can take:lot of time. Some scientists are now designing silicon computer chips that act like human organs. The scientists think they have found a way to make the process faster and more economical. The silicon computer chips are smaller than a child's hand. Each one has living cells that act and react like a human organ. The chips are being created as part of a program to test the safety of drug compounds. It is called the Tissue Chip for Drug Screening Program. It is a project of the US National Center for Advancing Tmnslational Sciences, or NCATS. Danilo Tagle is the center's Associate Director. He says a three-dimensional computer chip can be designed to act like a human lung. Some computer chips contain very small models of the human digestive system. They copy the real function or duties of the human stomach and intestine , moving when breaking down food. Drugs are added to the tiny organs for testing through instruments known as micro-tubes. Experiments with the tissue chips have produced more detailed information than tests using animal or cell models. NCATS just announced$17 million in grants to develop an entire human organ system over the next three years.
Question: Why are scientists designing silicon computer chips acting like human organs?
Options: (A) To treat the patients whose body organs don't work well. (B) To examine the health condition of human organs. (C) To make testing new drugs faster and cheaper. (D) .To further study the function of human organs.
[EX A]: C

[EX Q]: Article: Recently the busiest person on the Internet is absolutely Yuanfang, a fictional figure from the Chinese TV series "Detective Di Renjie". In the TV series, Li was often asked by Di, "How do you see it, Yuanfang?" Then, the dialogues between them help advance the plot. Now, the casual pet phrase is used as many as 2.5 million times by netizens in a single day, according to statistics. In fact, it is not the first popular sentence pattern on the Internet. Many other types of popular network words include those evolved from "the slogans of Vancl " and actor's lines of "The Legend of Concubine Zhen Huan". The explosive spread of the sentence "How do you see it, Yuanfang?" again proved the vast power of the network spread. The appearance of a buzzword on the Internet may be coincidental, but the spread of numerous buzzwords has started a social and cultural phenomenon. It is more noticeable that the spread is not _ but by chance. Usually, everyone has known about it, except the one concerned. The appearance of buzzwords is resulting from the agreement of netizens. If something is new and interesting enough, it will cause public attention. The rise of these buzzwords also benefits from their strong "adhesive force". After analyzing these buzzwords, we find that they have a common character, namely "novel in structure but empty in content". Therefore, any concrete contents can be added in these buzzwords, creating fantastic results. Taking the "Yuanfang-style" as an example, its popularity displayed a social mentality of questioning. Although it seems a little funny to ask "Yuanfang", a fictional character, and some people even find it boring. This way of asking a question reveals a valuable quality-listening. The Internet provides a space for everyone to express their views, but it also causes controversies. What's your opinion, Yuanfang?
Question: We can learn from the passage that Yuanfang _ .
Options: (A) is the busiest person in modern industrial societies (B) plays an important role in a Chinese TV series (C) is a fictional figure currently popular with netizens (D) starts a social and cultural phenomenon by himself
[EX A]:
C