You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

[EX Q]: Background Paragraph: Regions on the Earth's surface (or in its atmosphere) that are high above mean sea level are referred to as high altitude. High altitude is sometimes defined to begin at 2,400 meters (8,000 ft) above sea level.[5][6][7]

At high altitude, atmospheric pressure is lower than that at sea level. This is due to two competing physical effects: gravity, which causes the air to be as close as possible to the ground; and the heat content of the air, which causes the molecules to bounce off each other and expand.[8]. 
Story: There was a competition for who can get the model plane highest into the air. Team 1 got it 1,000 ft. Team 2 got it 2,000 ft. Team 3 go it 4,000 ft. Team 4 got it 9,000 ft. Team 5 got it 10,000 ft. Team 6 got it 12,000 ft. Team 7 got it 13000 ft. Team 7 won the contest and got a gold trophy as the prize. 
Question: What team got their kite into high altitude: Team 3 or Team 7?
[EX A]: Team 7.

[EX Q]: Background Paragraph: The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to loss of deltaic wetlands. 
Story: Jill lives out in a peaceful quiet area with hardly any other people around. Next to her home is a calm peaceful river. The river doesn't have an official name that she is aware of, but her family has always called it River Treetop due to the large tree next to it. Also next to her house, there is a roaring river that runs for miles. The river is so loud that it can be hard to hear yourself think sometimes if you are sitting next to it. For this reason, Jill has always referred to the river as River Chaos. 
Question: Which body of water is more concentrated with dissolved oxygen?
[EX A]: River Chaos.

[EX Q]: Background Paragraph: Common foodborne viruses include norovirus and hepatitis A virus. Norovirus, which causes inflammation of the stomach and intestines, has been a recent issue on cruise ships, infecting hundreds of passengers and crew on certain voyages. Hepatitis A causes inflammation of the liver, which is treated with rest and diet changes. Parasites are tiny organisms that live inside another organism. Giardia is a parasite spread through water contaminated with the stools of people or animals who are infected. Food preparers who are infected with parasites can also contaminate food if they do not thoroughly wash their hands after using the bathroom and before handling food. Trichinella is a type of roundworm parasite. People may be infected with this parasite by consuming raw or undercooked pork or wild game. 
Story: Two groups of tourists went on two different cruise ships Group J  had some members contract Norovirus and hepatitis A, while group K got many cases of giardia and trichinella infections. 
Question: Which group had fewer people with inflammation of the liver?
[EX A]:
group K.