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.
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Question: Article: Life in the Clear Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet--as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, "These animals live through their life alone. They never touch anything unless they're eating it, or unless something is eating them." And they are as clear as glass. How does an animal become see-through? It's trickier than you might think. The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter light, bouncing it away from its original path. Others absorb light, stopping it _ in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily. But a transparent object doesn't absorb or scatter light, at least not very much, Light can pass through it without bending or stopping. That means a transparent object doesn't look very different from the surrounding air or water. You don't see it ----you see the things behind it. To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering. Animals are built of many different materials----skin, fat, and more----and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see--through. Others build a large, clear mass of non-living jelly-lie material and spread themselves over it . Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.
Question: One way for an animal to become transparent is to _ .
Options: (A) change the direction of light travel (B) gather materials to scatter light. (C) avoid the absorption of light (D) grow bigger to stop light.

Answer: C

Question: Article: Remember, from the moment they are born, our children have the ability to know when they are hungry - and they cry to let us know too! Of course, they also cry to let us know they are wet, hurt, or bored, but we soon learn to tell the difference and try to meet each need somehow. When we begin to feed them solid foods, they let us know when they have had enough by turning away from the spoon - or refusing the food back at us! Why is it that once children are old enough to sit at the table their parents are often heard bargaining with them or threatening them to finish all their dinner? When we make our children eat up the plate that we filled, we don't pay attention to their born ability to know how much, and what, their bodies need. Instead, we should allow them to use their own hunger feelings to determine how much they need, while we provide a balance of nutritious and "fun" foods. When we teach them about moderation and set a great example by living an active, healthy lifestyle, they will be less likely to develop weight problems later in life. Think of your slim friend who eats whatever she wants -but will refuse ice cream if she has had enough to eat! "Eat all your dinner if you want dessert" translates to "you must overeat so I will reward you by letting you overeat some more!" By using sweets as a reward for good behavior, kids begin to believe sweets are really special and they may want them even more. Instead, by making dessert just another (small) part of an enjoyable meal, kids learn to "save room for dessert" instead of becoming a member of the "clean plate club."
Question: Children are born to know _ .
Options: (A) how to stay away from poison (B) how much they should take when hungry (C) meat is worse than vegetables (D) sugar is better than fat

Answer: B

Question: Article: Only if you don't have a fear of heights do you want to visit the CN Tower. And if you can take a trip to the top of it will surely be worth it. The CN tower is Canada's most famous symbol and the centre of tourism in Toronto. Over 550 meters, it is one of the tallest building in the world; on a clear day the view is wonderful. Each year, around 2 million people take the elevator ride to the top of the tower to take in the breath-taking view at the top of the world. Once you are at the top, see if you have the courage to walk across the see-through glass floor . If you are hungry, plan to eat at the revolving restaurant at the top of the tower. The floor in the 360-degree restaurant rotates once every 72 minutes allowing everyone a complete view of the city below. The CN tower has broken record many times, winning such titles as World's Longest Metal staircase ,World's Tallest building and , most recently , World's Highest Wine Cellar. In 1995, the CN tower was considered as one of the seven wonders of the Modern World. Today, the top of the tower, more than 333m in the air, serves as the year-round workplace for more than 550 people. The tower's workers help to make the world-class attractions and food there. While at the CN tower, you'll also have the chance to visit gift shops. You will find the CN Tower in the heart of downtown, on Front Street. On the north shore of Lake Ontario, the CN Tower is open 364 days a year(closed on Christmas Day).
Question: Who can't visit the CN tower?
Options: (A) Someone who has heart attack. (B) An old man who has got flu. (C) A person afraid of height (D) A woman having high blood.

Answer:
C