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 Input:
Background Paragraph: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution that harms the health of living things. The air pollution also causes acid rain and contributes to global warming. In addition, fossil fuels are nonrenewable resources, so if we keep using them, they will eventually run out. The main advantage of nuclear energy is that it doesn’t release air pollution or cause the other environmental problems associated with the burning of fossil fuels. On the other other hand, radioactive elements are nonrenewable like fossil fuels and could eventually be used up. 
Story: Thorn county used fossil fuels for their energy needs, while Plant county used nuclear power. They both polluted the environment in different ways. 
Question: Which county released more air pollution?

Ex Output:
Thorn.


Ex Input:
Background Paragraph: A dilution effect is seen when animals living in a group "dilute" their risk of attack, each individual being just one of many in the group. George C. Williams and W.D. Hamilton proposed that group living evolved because it provides benefits to the individual rather than to the group as a whole, which becomes more conspicuous as it becomes larger. One common example is the shoaling of fish. Experiments provide direct evidence for the decrease in individual attack rate seen with group living, for example in Camargue horses in Southern France. The horse-fly often attacks these horses, sucking blood and carrying diseases. When the flies are most numerous, the horses gather in large groups, and individuals are indeed attacked less frequently. Water striders are insects that live on the surface of fresh water, and are attacked from beneath by predatory fish. Experiments varying the group size of the water striders showed that the attack rate per individual water strider decreases as group size increases. 
Story: Mike was visiting the African Savannah. One animal that interested him most was the African Buffalo. He noticed that the buffaloes would usually live in a large herd, often exceeding few hundreds. He noted that as case A. But sometimes the buffaloes would live in a small herd. He noted that as case B. Interestingly, there are incidents when an aggressive male buffalo would live by itself. He noted that as case C. 
Question: In which case the group would get more benefit as a whole, case A or case B?

Ex Output:
case B.


Ex Input:
Background Paragraph: Start right above point on the temperature axis and follow the red line vertically. At very low pressure, the particles of the substance are far apart from one another and the substance is in the gas state. As the pressure is increased, the particles of the substance are forced closer and closer together. Eventually the particles are pushed so close together that attractive forces cause the substance to condense into the liquid state. Continually increasing the pressure on the liquid will eventually cause the substance to solidify. For the majority of substances, the solid state is denser than the liquid state and so putting a liquid under great pressure will cause it to turn into a solid. The line segment represents the process of sublimation, where the substance changes directly from a solid to a gas. At a sufficiently low pressure, the liquid phase does not exist. The point labeled is called the triple point . The triple point is the one condition of temperature and pressure where the solid, liquid, and vapor states of a substance can all coexist at equilibrium. 
Story: John is learning about different states of matter. So far, he recognized three states of matter, state A, state B, and state C. State A is in solid state. State B is in liquid state, and state C is in gaseous state. He needs to learn more about their individual characteristics. 
Question: Which state would have higher pressure, state B or state C?

Ex Output:

state B.