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.

Example Input: Article: Recent research has claimed that an excess of positive ions in the air can have an ill effect on people's physical or psychological health. What are positive ions? Well, the air is full of ions, electrically charged particles, and generally there is a rough balance between the positive and the negative charged. But sometimes this balance becomes disturbed and a larger proportion of positive ions are found. This happens naturally before thunderstorm, earthquakes when winds are blowing in certain countries. Or it can be caused by a build-up of static electricity indoors from carpets or clothing, or from TV sets, duplicators or computer display screens. When a large number of positive ions are present in the air many people experience unpleasant effects such as headaches, fatigue , excessive anger, and some particularly sensitive people feel sick or even suffer mental disturbance. Animals are also affected, particularly before earthquakes, snakes have been observed to come out, rats to flee from their burrows, dogs howl and cats jump about unaccountably. This has led the US Geographical Survey to fund a network of volunteers to watch animals in an effort to foresee such disasters before they hit vulnerable areas such as California. Conversely, when large numbers of negative ions are present, then people have a feeling of well-being. Natural conditions that produce these large amounts are near the sea, close to waterfalls or fountains, or in any place where water is sprayed, or forms a spray. This probably accounts for the beneficial effect of a holiday by the sea, or in the mountains with streams or waterfalls. To increase the supply of negative ions indoors, some scientists recommend the use of ionisers. They claim that ionisers not only clean and refresh the air but also improve the health of people sensitive to excess positive ions. Of course, there are the detractors, other scientists, who dismiss such claims and are skeptical about negative/positive ion research. Therefore people can only make up their own minds by observing the effects on themselves, or on others, of a negative rich or poor environment. After all it is debatable whether depending on seismic readings to anticipate earthquakes is more effective than watching the cat.
Question: What is an ion according to the passage?
Options: (A) It's a charged particle. (B) It's basically static electricity indoors. (C) It's a balance between the positive and negative charged. (D) It's an ill effect on people's physical and psychological health.
Example Output: A

Example Input: Article: When the US started the war in Iraq a year ago, Spain was a firm supporter. But on April 18, the Spanish government started to remove its troops, becoming the first country in the US-led coalition to bring its soldiers home. The person behind this surprise move is the new Spanish prime minister, Jose Luis Rodriguez Zapatero. A few months ago, he was hardly known outside his small hometown in northern Spain. Even a week before last month's general election, Zapatero was still considered an outsider for the top job. But just three days before the vote, a series of bomb attacks on three train stations in Madrid killed 191 people and injured some 1,900. It was Spain's worst ever terrorist attack and it changed everything -- even making Zapatero prime minister. From the beginning, the 43-year-old former lawyer, knew the weaknesses of Prime Minister Jose Maria Aznar and his hand-picked successor, Mariano Rajoy. About 90 per cent of the Spanish people were against the war in Iraq and were unhappy that Aznar had taken them into it. So Zapatero promised: "If this party wins the election and the UN still can't take charge in Iraq, the new government will pull its 1,400 troops out of Iraq." Despite focusing on this and other Aznar mistakes, Zapatero's chances of victory were still thin until the Madrid bombings. At first, the government blamed ETA, a separatist terror group from the Basque region of northern Spain. But later evidence suggested the attack was carried out by al-Qaida members angry at Spain's presence in Iraq. The people were upset, and they showed this by voting for Zapatero. Many accused the government of covering up information about the bombings and only blaming ETA so it wouldn't lose to an anti-war vote. In a move that was as shocking to the world as his election victory, Zapatero chose to carry out his promise the day after he took office. And its effect could be long-lasting. As the situation in Iraq worsens, several countries are considering their positions. The US is worried that other coalition members might follow Spain's lead and also bring their soldiers home.
Question: Why did the Spanish government try to hide the truth from the public at first?
Options: (A) They feared the terrorists would escape. (B) They were not quite sure who on earth made the attacks. (C) They were worried that they would lose the coming election. (D) They attempted to get rid of all ETA members.
Example Output: C

Example Input: Article: A child's birthday party doesn't have to be a _ ; it can be a basket of fun, according to Beth Anaclerio, an Evaston mother of two, ages 4 and 18 months. "Having a party at home usually requires a lot of running around on the part of the parents, and often the birthday boy or girl gets lost in wild excitement. But it really doesn't have to be that way," said Anaclerio. Last summer, Anaclerio and her friend Jill Carlisle, a Northbrook mother of a 2-year -old, founded a home party-planning business called "A Party in a Basket." Their goal is to help parents and children share in the fun part of party planning, like choosing the subject or making a cake, while they take care of everything. Drawing on their experiences as mothers, they have created 10 ready-to-use, home party packages. Everything a family needs to plan a party, except the cake and ice cream, is delivered to the home in a large basket. "Our parties are aimed for children 2 to 10, " Anaclerio said, "and they're very interactive and creative in that they build a sense of drama based on a subject. For example, at the Soda Shoppe party the guests become waiters and waitresses and build wonderful ice cream creations." The standard $ 200 package for eight children includes a basket filled with invitations, gifts, games and prizes, paper goods, a party planner and the like. For more information, call Anaclerio at 708-864-6584 or Carlisle at 708-205-9141.
Question: The main purpose of writing this text is _ .
Options: (A) to share information about party planning (B) to introduce the joys of a birthday party (C) to announce a business plan (D) to sell a service
Example Output:
D