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: Winter begins in the north on December 22nd. People and animals have been doing what they always do to prepare for the colder months. Squirrels , for example, have been busy gathering nuts from trees. Well, scientists have been busy gathering information about what the squirrels do with the food they collect. They examined differences between red squirrels and gray squirrels in the American state of Indiana. The scientists wanted to know how these differences could affect the growth of black walnut trees. The black walnut is the nut of choice for both kinds of squirrels. The black walnut tree is also a central part of some hardwood forests. Rob Swihart of Purdue University did the study with Jake Goheen, a former Purdue student now at the University of New Mexico. The two researchers estimate that several times as many walnuts grow when gathered by gray squirrels as compared to red squirrels. Gray squirrels and red squirrels do not store nuts and seeds in the same way. Gray squirrels bury nuts one at a time in a number of places. But they seldom remember where they buried every nut. So some nuts remain in the ground. Conditions are right for them to develop and grow the following spring. Red squirrels, however, store large groups of nuts above ground. Professor Swihart calls " _ ". Gray squirrels are native to Indiana. But Professor Swihart says their numbers began to decrease as more forests were cut for agriculture. Red squirrels began to spread through the state during the past century. The researchers say red squirrels are native to forests that stay green all year, unlike walnut trees. They say the cleaning of forest land for agriculture has helped red squirrels invade Indiana. Jake Goheen calls them a sign of an environmental problem more than a cause.
Question: The study done by Rob Swihart and Jake Goheen is to _ .
Options: (A) find out the living conditions for squirrels (B) learn squirrels' influence on black walnut trees (C) do something to get rid of squirrels (D) save the forests in the American state of Indiana
[EX A]: B

[EX Q]: Article: Why do people run? That is, why do thousands get up early and put their knees and ankles and hearts and lungs through the hell of 10,000 meters on the roads? For those who stick with it and are lucky, they get into another world: a state of physical and mental grace reached when their blood is racing through every vein . And in Austin, those who long to get better, even when they know it's impossible, hang on Gilbert's every word. Gilbert's methods are simple. It's all about form: how the arms move and the feet land. He pushes his students hard. When they feel like they're about to die, they look at Gilbert's scars -- the burns along his right arm, and then to his right leg, where the flames ate down to the bone. Whatever they feel, how bad, really, could it be? "He gets people to believe in themselves," says Lisa Spenner, one of the _ , who are crazy about Gilbert. "He treats everyone like they're amazing." If Gilbert is their savior, they are his saviors too. "Eventually, I realized I had to help people. When I help people, I feel good," he says. Gilbert's right leg was so badly burnt that the knee was stuck at a 90-degree angle. The doctor said it would take six months to heal. Frustrated, Gilbert got on a bike. The biking led to walking, which finally led to running a year after he had been left to die. In truth, runners don't race other runners. They race against themselves to conquer their wills. So Gilbert spent the spring and summer of 2007 trying to do that, racing men faster than he is, knowing it would make him better. Gilbert's students, of course, keep rooting for him, though sometimes they wonder, "How much better can he get?" After all, they see him as more than just a runner and a coach. He's a flesh-and-blood symbol: the daily struggle to show what you're made of.
Question: What do we learn about Gilbert after reading the passage?
Options: (A) He used to work as a fireman. (B) He has determination and strong will-power. (C) He learnt running from a coach. (D) He was advised to ride a bike when he was badly burnt.
[EX A]: B

[EX Q]: Article: Experts say the temperature in Eyjafjallajokull's hole appears to have fallen to 100C, meaning it is now producing steam, not magma . But officials warned that it was too early to say whether the eruption was over completely. Ash clouds from the volcano grounded thousands of flights last month. Steinunn Jakobsdottir, a geophysicist from the Icelandic Meteorological Office, told the BBC that the volcano was "kind of not active for the moment". "The history of the volcano is such that it calms down and then it gets energy again," she said. "There are still earthquakes under the volcano, and the small earthquake is still not quite down to what it was before the eruption." 'Difficult to say' Magnus Gudmundsson, of Iceland University, flew over the volcano on Sunday and said information from heat cameras showed the temperatures at the crater had fallen below 100C. But he told the AFP news agency that nothing was promised and that the previous eruption at the volcano had lasted 13 months, from 1821-23. "It stopped and started again several times with different intervals , so it's difficult to say, difficult to give a timeline," he said. He also said it was impossible to say whether the neighbouring Katla volcano - a much larger mountain - might also erupt. At the height of its activity, the volcano sent out huge clouds of ash, which led to airlines grounding their planes for fear it could _ plane engines. It was the biggest action of closing airspace in Europe since World War II, and affected at least 10 million passengers worldwide.
Question: What do expert think Eyjafjallajokull is like now?
Options: (A) Magma is still coming out (B) The hole appears about 100 degrees C (C) The eruption was not over (D) It is very cold.
[EX A]:
B