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: 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: When I first got an e-mail account ten years ago, I received communications only from family, friends, and colleagues. Now it seems that every time I check my e-mail,I have an endless series of advertisements and other _ that do not interest me at all. If we want e-mail to continue to be useful, we need specific laws that make spamming a crime. If lawmakers do not do something soon to prohibit spam, the problem will certainly get much worse. Computer programs allow spammers to send hundreds of millions of e-mails almost instantly. As more and more advertisers turn to spam to sell their products,individual e-mail boxes are often flooded with spam e-mails. Would people continue to use e-mail if they had to deal with an annoying amount of spam each time? This problem is troubling individuals and companies as well. Many spam e-mails contain computer viruses that can shut down the entire network of a company. Companies rely on e-mail for their employees to communicate with each other. Spam frequently causes failures in their local communications networks, and their employees are thus unable to communicate effectively. Such a situation results in a loss of productivity and requires companies to repeatedly repair their networks. These computer problems raise production costs of companies, which are, in the end, passed on to the consumer. For these reasons, I believe that lawmakers need to legislate against spare. Spammers should be fined, and perhaps sent to prison if they continue to disturb people. E-mail is a tool which helps people all over the world to communicate conveniently, but spam is destroying this convenience.
Question: According to the text, what is the major cause of the flooding spam?
Options: (A) Companies rely on e-mail for communications. (B) More people in the world communicate by e-mail. (C) Many computer viruses contain spam e-mail. (D) More advertisers begin to promote sales through spam.

Ex Output:
D

Ex Input:
Article: When American inventor Alexander Graham Bell invented the telephone in 1876, it was a revolution in communication. For the first time, people could talk to each other over great distances. Over the last two decades a new means of spoken communication has appeared: the mobile phone. The mobile phone is like a two-way radio. But the two-way radio is a limited means of communication. As soon as the users move out of range of each other's broadcast area, the signal is lost. In the 1940s, researchers experimented with the idea of using a number of radio masts to pick up signals from two-way radios. A caller would always be within range of one of the masts. When he or she moved too far away from one mast, the next mast would pick up the signal. (Scientists referred to each mast's reception area as being a "cell". This is why in many countries mobile phones are called "cellphones".) However, 1940s' technology was just at the beginning. The "mobile phones" were huge boxes. They had to be moved by car. The first real mobile telephone call was made in 1973 by Dr Martin Cooper. As soon as his invention was complete, he tested it by calling a rival scientist to announce his success. Within a decade, mobile phones became available to the public. They have changed the way we do a lot of things. One powerful feature is: the short message service (SMS) or text message. It's the perfect communication method for the busy modern lifestyle. The text message has changed the way we write in English. The language construction became more lax . Traditional rules of grammar and spelling are much less important. Over the last few years mobiles have become more and more advanced. We have seen the introduction of cameras, global positioning system and Internet access. Alexander Graham Bell would be surprised if he could see how far the science of the telephone has developed in less than 150 years. If he were around today, he might say: '''That's gr8! But I'm v busy rite now. Will call U 2nite.'
Question: The article is intended to _ .
Options: (A) warn people of the possible risks in using mobile phones (B) inform readers of the history and benefits of mobile phones (C) convince people of the uses of mobile phones (D) predict the applications of mobile phones

Ex Output:
B