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: Language is always changing. In a society where life continues year after year with few changes, the language does not change either. The earliest known languages had difficult grammar but a small, limited vocabulary. Over the century, the grammar changed, and the vocabulary grew. For example, the English and Spanish people who came to America during the sixteenth century gave names to all the new plants and animals they found. In this way, hundreds of new words were introduced into English and Spanish vocabularies. Today life is changing very fast, and language is changing fast too. There are several major language families in the world. Some scientists say there are nine main families, but other scientists divide them differently. The languages in each family are connected, and scientists think that they came from the same parent language. About 3 percent of the people in the world speak languages that are not in these major families.
Question: The early language had _ .
Options: (A) a lot of problems (B) words and easy grammar (C) words but no grammar (D) grammar but not many words

Ex Output:
D

Ex Input:
Article: Each time I see a balloon, my mind flies back to a memory of when I was a six-year-old girl. It was a rainy Sunday and my father had recently died. I asked my mom if Dad had gone to heaven. "Yes, honey. Of course." she said. "Can we write him a letter?" She paused, the longest pause of my short life, and answered, "Yes." My heart jumped. "How? Does the mailman go there?" I asked. "No, but I have an idea." Mom drove to a party store and returned with a red balloon. I asked her what it was for. "Just wait, honey. You'll see." Mom told me to write my letter. Eagerly, I got my favorite pen, and poured out my six-year-old heart in the form of blue ink. I wrote about my day, what I learned at school, how Mom was doing, and even about what happened in a story I had read. For a few minutes it was as if Dad were still alive. I gave the letter to Mom. She read it over, and a smile crossed her face. She made a hole in the corner of the letter where she looped the balloon string. We went outside and she gave me the balloon. It was still raining. "Okay, on the count of three, let go. One, two, three." The balloon, carrying my letter, darted upward against the rain. We watched until it was swallowed by the mass of clouds. Later I realized, like the balloon, that Dad had never let his sickness get him down. He was strong. No matter what he suffered, he'd persevere, dart up, and finally transcend this cold world and his sick body. He rose into sky and became something beautiful. I watched until the balloon disappeared into the gray and white and I prayed that his strength was hereditary. I prayed to be a balloon.
Question: When the girl asked her mother if they could write to her father, her mother _ .
Options: (A) felt it hard to answer (B) thought her a creative girl (C) believed it easy to do so (D) found it easy to lie

Ex Output:
A

Ex Input:
Article: This morning, a Virgin Atantin 747 Jumbo Jet became the first commercial airplane to fly on biofuel. The short flight from London to Amsterdam used a blend of 20% babassu oil mixed with 80% conventional jet fuel. What was really exciting about the flight was the fact that the engine did not have to be altered in any way for the biofuel to work While this is a great initial step in trying to reduce CO2(carbon-dioxide)emissions from airplanes. there are a lot of hurdles that still need to be overcome. First and foremost, unlike the normal fuel used to run airplanes (known as Jet A),biofuel freezes at high altitudes. Also, Jet'A'fuel burns consistently (at the same pace),which means it provides a safe and reliable fuel for long flights--engineers are not sure if biofuel will be able to do the same. The biggest hurdle to a full biofuel switch is our ability to be able to grow enough crops that can be converted to biofuel. There are two concerns that scientists have in this matter - the first is that the land to grow the extra crops will come from clearing more of our forests and the second is that since it competes with what we eat, the price of food will go up. However, Richard Branson of Virgin Airlines, envisions that if biofuel starts to replace oil on a greater basis, it will be manufactured from algae produced in sewage treatment plants, not from food sources. Birgin Airlines is not the only one trying to look for alternative fuel sources. Earlier this year, an Airbus A380 used another alternative fuel-a man-made mix of gas-to-liquid, in one of its four engines. The flight was tested by Rolls Royce (manufacturer of jet engines), in partnership with Shell (an oil company). Rolls Royce is also working with Air New Zealand on a similar project. While a complete switch to alternative fuel may take years, it is very encouraging to see airlines, oil companies and airplane manufacturers all coming together to try to make it happen!
Question: .Why does Virgin Airlines try to replace normal fuel with biofuel?
Options: (A) To cut down the flight cost of the company. (B) To remove some hurdles for the biofuel to work. (C) To reduce CO
2 emissions from airplanes. (D) To test plane engines on biofuel.

Ex Output:
C