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: Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death. 
Story: Two teams of researchers studied different diseases. team Alpha studied people with cholesterol, while team Beta studied people with Parkinson's disease. 
Question: Which team studied more people with restricted blood flow to the heart muscle?
[EX A]: Alpha.

[EX Q]: Background Paragraph: Specific humidity (or moisture content) is the ratio of the mass of water vapor to the total mass of the moist air parcel.[13] Specific humidity is approximately equal to the mixing ratio, which is defined as the ratio of the mass of water vapor in an air parcel to the mass of dry air for the same parcel. As temperature decreases, the amount of water vapor needed to reach saturation also decreases. As the temperature of a parcel of air becomes lower it will eventually reach the point of saturation without adding or losing water mass. 
Story: Tho towns located on opposite banks of a river, had a humid season, but Bend town had a cooler air at night. Bank town on the other hand, had warmer nights because it was situated on a south facing hill. 
Question: Which town experienced a higher specific humidity?
[EX A]: Bend.

[EX Q]: Background Paragraph: Hydrogen bonds cause water to have a relatively high boiling point of 100°C (212°F). Because of its high boiling point, most water on Earth is in a liquid state rather than in a gaseous state. Water in its liquid state is needed by all living things. Hydrogen bonds also cause water to expand when it freezes. This, in turn, causes ice to have a lower density (mass/volume) than liquid water. The lower density of ice means that it floats on water. For example, in cold climates, ice floats on top of the water in lakes. This allows lake animals such as fish to survive the winter by staying in the water under the ice. 
Story: Bill was studying the states of matter. First, he selected a matter with low boiling point. He labeled it as matter A. To compare it with a well-known matter he selected water. He labeled it as matter B. He also selected ice, which he labeled as matter C. He is now better prepared to compare their states. 
Question: Which would have lower density, matter B or matter C?
[EX A]:
matter C.