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: All plant cells are capable of taking up water. Even dead ones do to a certain degree. Absorption of water by dead cell walls makes wood become larger. In common land plants, the living cells of roots take upmost of the water. Land plants without roots do exist, however. Those greenish-yellow lichens you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots. Even among the flowering plants, one finds rootless forms. These flowering plants are "the higher plants" because they evolved recently and are thus considered higher on the evolutionary scale . In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies. In the southern United States and in Puerto Rico, one sees growing high above the streets on the insulation of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.
Question: Wood becomes larger because of _ .
Options: (A) dead cell walls (B) water entering dead cells (C) the growth of cells (D) the death of cells

Ex Output:
B

Ex Input:
Article: Perhaps the most extraordinary building put up in the nineteenth century was the Crystal Palace which was built in Hyde Park for the Great Exhibition of 1851. The Crystal Palace was different from all the other buildings in the world, for it was made of iron and glass. It was one of the biggest buildings of all the time and a lot of people from many countries came to see it. Plenty of goods were sent to the exhibition from all parts of the world. There was also a great deal of machinery on show. Though in those days, traveling was not as easy as it is today, steamboats carried thousands of visitors across the Channel from Europe. On arriving in England, they were taken to the Crystal Palace by train. There were six million visitors in all, and the money from the exhibition was used to build museums and colleges. Later the Crystal Palace was moved to the South London. It remained one of the most famous buildings in the world until it was burnt down in 1936.
Question: The Crystal Palace was built up _ .
Options: (A) in the 1950s (B) in the 1900s (C) shortly before 1851 (D) before 1951

Ex Output:
C

Ex Input:
Article: One important attraction of walking is its long-lasting appeal. Whereas jogging and aerobic dancing can _ quickly, walking provides a popular activity that seems to endure. Fitness foundations estimate that 35 million adult Americans walk for exercise every day, with at least 15 million walking two or three times a week. Among the most regular walkers are those 65 years and older--evidence that walking is an exercise that lasts. In addition to its many physical benefits, walking, like other physical activities, has a comforting effect on the psyche. Walking can help you to think more clearly and feel more relaxed. It also can be a sociable activity. An early morning walk around the neighborhood provides an opportunity to chat with friends or simply admire the flowers. Or because it does not require a team or even a partner, walking is something you can do on your own time, by yourself, whenever the mood strikes. Easily affordable, all you need to start walking is enthusiasm and a pair of comfortable and sturdy low-heeled shoes. Dr.ChristineL. Wells recommends an Oxford-style shoe with ties for better foot support; she does not recommend sneakers or other "cheapies". If you plan to walk regularly, you might want to invest in a pair of so-called walking shoes. If so, expect to spend at least $35. For walking during the hotter months, early morning or evening hours are best. Clothes should fit loosely and be lightweight and light-colored. Elderly walkers should consider wearing long sleeves, and all Arizonans need to be particularly concerned about skin cancer. Dr. Wells suggests wearing sunscreen as well as a side-brimmed hat to protect your eyes, ears, nose and back of the neck. Walkers also should drink an adequate amount of water. Wells advises drinking an 8-ounce glass of water before you start out, and more when you return. "If you walk four miles or more a day in Arizona, I also recommend that you carry a water bottle," she says. " And water is just fine; you don't need those fluid-replacement or electrolyte drinks."
Question: Which of the following is NOT mentioned as a benefit of walking?
Options: (A) It improves one's appetite. (B) It's an inexpensive exercise (C) It helps to comfort the mind. (D) it can be an individual or social activity

Ex Output:
A