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: Water is of vital importance in a healthy diet and lifestyle. There are many health benefits of drinking water .It helps get _ out of our systems. It aids in the delivery of oxygen and nutrients .In fact, nearly every system in our bodies depends on water for proper functioning .But how can we tell whether the water we're drinking is healthy? As to tap water, it's relatively easy .If your water comes from a governmental source , the suppliers are required by law to provide annual water quality reports .If you have a well, you can have an authorized lab test your water .It may cost $100 or more, but it's a small price to pay for peace of mind . When it comes to bottled drinking water, it can be more difficult to know what you're getting .Start by checking the label or the bottle cap. Some may tell you that the water comes from a governmental source or "community water system", which means tap water .If the label doesn't give any information, you can call the bottler and ask .But don't be surprised if you get the runaround and are transferred to several different departments .Some states have a bottled water program that tracks bottled drinking water and can tell you the origin of the water as well as other information . Safe and healthy drinking water has become big business .Thousands of companies are competing for your hard earned cash , and some are not always honest about what their products offer .The initial investment in a home drinking water filtration system can seem expensive at first , but over time , it is usually less expensive than bottled drinking water .And with a water filter , you at least know where the water you drink comes from and how it is treated . Before going out and spending your hard earned money on bottled drinking water , it's a good idea to do some research .You're likely to find that a drinking water filtration system or purifier is a healthier choice and provides the best value as well .
Question: By using a water filter, people _
Options: (A) can drink water without fearing that the water isn't treated (B) will have to pay more money eventually than if they just drink bottled water (C) will know if the water company is honest or not (D) can check the quality of the water by themselves.
Example Output: A

Example Input: Article: Many people say dolphins are very intelligent. They seem to be able think, understand, and learn things quickly. But they are smart like humans or more like cats or dogs? Dolphins use their brains differently from people. But scientists say dolphin intelligence and human intelligence are alike in some ways. How? FACT 1: Talk to Me Like humans, every dolphin has its own "name". The name is a special whistle . Each dolphin chooses a specific whistle for itself, usually by its first birthday. Actually, scientists think dolphins, like people, "talk" to each other about a lot of things, such as their age, their feelings, or finding food. And, like humans dolphins use a system of sounds and body language to communicate. But understanding their conversations is not easy for humans. No one "speaks dolphin" yet, but some scientists are trying to learn. FACT 2: Let's Play Dolphins are also social animals. They live in groups called pods, and they often join others from different pods to play games and have fun ---just like people. In fact, playing together is something only intelligent animals do. FACT 3: Fishermen's Helpers Dolphins and humans are similar in another way: both make plans to get something they want. In the sea of southern Brazil, for example, dolphins use a interesting strategy to get food. When fish are near a boat, dolphins signal to the fishermen to put their nets in the water. Using this method, the men can catch a lot of fish. What is the advantage for the dolphins? Why do they assist the men? The dolphins get to eat some of the fish.
Question: What is the text mainly about?
Options: (A) The comparison between dolphins and humans. (B) The relationship between dolphins and humans. (C) Different types of dolphins. (D) The habitual behavior of dolphins.
Example Output: A

Example Input: Article: Water skiing is a sport with many social, economic and health benefits to society. It is unique in that it is a sport where able and disabled persons, and people as young as 5 years and as old as 80 years of age can participate alongside each other. It is a sport that involves more than one person, and is a wonderful family activity that gathers members together for a day of fun at a favorite waterway. Anyone who has put on water skis can attest to its health benefits--it is a sport that demands and develops strength, agility and endurance. The sport includes several disciplines including slalom, tricks, cable, jump, ski racing, kneeboard, wakeboard, and barefoot, with each of these practiced for either recreational or competitive enjoyment. Safety Tips for Water-Skiers Don't take unnecessary risks while water-skiing. The following tips will help you safely enjoy this thrilling sport: ALWAYS have an observer in the boat. This is a legal requirement in many states. The boat driver cannot watch the skier and operate the boat safely at the same time. ALWAYS wear a Coast Guard approved Personal Flotation Device (PFD) designed for water skiing. Ski belts are NOT recommended. Your approved PFD will help keep you afloat. NEVER ski in rough water. High waves or a choppy sea will prevent the tow boat from maintaining a steady course and speed. NEVER ski after dark. It is dangerous AND illegal. Any boat traveling fast enough to tow a skier is traveling too fast to navigate safely at night. NEVER water-ski while under the influence of alcohol or drugs. Such activity is extremely dangerous because of the impairment to your judgment and ability to respond. A recent study conducted with expert skiers who were purposely drunk indicated that even their ability to ski was dramatically reduced. Use hand signals between the skier and observer. Agree before you start what each signal means so there is no confusion at a critical moment.
Question: Who can accompany you to go water skiing?
Options: (A) A pupil in a primary school. (B) A person who is disabled. (C) A family member. (D) All above.
Example Output:
D