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: Mary Jean Price Walls graduated second in her class in 1950.She had high hopes when she applied to a local college,Southwest Missouri State College.But after sending off her application,she spent months waiting for a reply.It never came. Worse than simply being denied admission ,the school didn't reply to her at all.It wasn't a matter of her school records,but of her skin color:Wallsis African American,and in those days,that fact alone closed a lot of doors. "I was sad and I was hurt,"Walls toldABCNews."I did not expect the skin color would affect my application.I thought I could go to university like other students." Four years later,the government declared that all schools should not discriminate against African Americans-- but it was too late for Walls.She'd moved on with her life, becoming a wife and a mother,and working as an elevator operator.She retired last year,at the age of 77. She stayed quiet about the unfairness she'd faced in Missouri State.Her son,Terry,went through school records and found that she'd been the first black student to ever apply to the college.Today,four percent of the Southwest Missouri State College body is African American--including Terry. Although it's too late for Missouri State to change the past,the school is awarding Walls with an honorary degree from the school.While she knows it's too late for herto change the course of her own life with the degree,it's a chance for her to show her family that Missouri State has changed in the last 60 years,and there's not a single door closed to them anymore.
Question: Walls couldn't enter the local college because _ .
Options: (A) her examination performance is too bad (B) girls were not allowed to go to college (C) she was an AfricanAmerican student (D) her parents had no enough money to support her

Ex Output:
C

Ex Input:
Article: Computer power is moving into the "cloud"--networks of data centres that use the Internet to supply all kinds of services, from e-mail and social networks to data storage and analysis. The rise of cloud computing is rapid and causing huge changes in the tech industry. The old guard is suffering: this week's $67 billion merger between Dell and EMC, makers of computers and storage devices respectively , was a marriage forced by the rise of the cloud. Disruptive newcomers are blooming: if Amazon's cloud-computing unit were a stand-alone public company, it would probably be worth almost as much as Dell and EMC combined. The gains for customers have been equally dramatic. Compared with older IT systems, cloud computing is often much cheaper. It adds tremendous flexibility: firms that need more computing capacity no longer have to spend weeks adding new servers and installing software. In the cloud they can get hold of it in minutes. Their applications can be updated continually, rather than just every few months. Individual users can reach their e-mails, files and photos from any device. And cloud services also tend to be more secure, since providers know better than their customers how to protect their computing systems against hackers. But cloud computing makes one problem worse. In the old IT world, once a firm or a consumer had decided on an operating system or database, it was difficult and costly to switch to another. In the cloud this "lock-in" is even worse. Cloud providers go to great lengths to make it easy to upload data. They accumulate huge amounts of complex information, which cannot easily be moved to an alternative provider. Cloud firms also create a world of interconnected services, software and devices, which is convenient but only for as long as you don't venture outside their universe. Being locked in to a provider is risky. Firms can start to tighten the screws by increasing prices. If a cloud provider goes bust , its customers may have trouble getting back their data. These risks have already caused a debate about whether the cloud needs stricter regulation. Some European politicians want to force cloud providers to ensure that data can be moved between them. That is too heavy-handed, because strict rules will inhibit innovation in what is still a young industry. The history of computing suggests that common standards may well appear naturally in response to customers' demands--just as in personal computers, where it is now much easier to use the same files on different systems. In the meantime, a few commonsense measures can reduce the risk of lock-in. Firms that use more than one cloud provider to host their data are less affected. So are those that keep their most important information in their own data centres. Consumers can take precautions, too. Some services are better than others at enabling users to move data between providers (Google does well on this score). Cloud computing promises its users many benefits, but don't mistake it for some sort of digital heaven.
Question: The author takes "the merger between Dell and EMC" for example to show _ .
Options: (A) the influence of cloud computing on computer and storage device makers (B) the miserable sufferings of old computer companies (C) the rapid development of new computer companies (D) the interaction between old companies and newcomers

Ex Output:
A

Ex Input:
Article: The Ice Hotel Are you going into skiing? Is winter your favorite time of year? If you like snow and ice, maybe you should stay at Ice Hotel in Quebec, Canada. But, you can only check in at this hotel during the winter. Why ? Because this hotel is built every December. It has 32 rooms and 80 people can stay there each night. The hotel even has a movie theatre, art gallery, and church. Of course, all of these parts of the hotel are made of ice. In fact, all the furniture, art, lights, and even plates and drinking glasses are made out of ice. Because this hotel is so unusual, it is becoming very popular. People from all over the world come to the Ice Hotel to look at the fantastic ice art, drink and eat from designed ice dishes and experience the unique atmosphere . Some couples have even got married in the hotel's ice church. But all these guests keep their winter coats on! Because of all the ice, the temperature inside the hotel is always between - 2oC and - 5oC. Surprisingly, sleeping is not a problem in the freezing cold hotel rooms. Every guest gets a special cold-weather sleeping bag and some fur blankets. These keep the room cozy and warm until morning.
Question: What is the main idea of this reading?
Options: (A) How the Ice Hotel is built (B) What makes the Ice Hotel special (C) Why the Ice Hotel is made of ice (D) The services of the Ice Hotel

Ex Output:
B