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.

Example Input: Background Paragraph: Protozoa generally feed by engulfing and digesting other organisms. As consumers, they have various roles in food chains and webs. Some are predators. They prey upon other single-celled organisms, such as bacteria. In fact, protozoa predators keep many bacterial populations in check. Other protozoa are herbivores. They graze on algae. Still others are decomposers. They consume dead organic matter. There are also parasitic protozoa that live in or on living hosts. For example, the protozoan that causes malaria lives inside a human host. For their part, protozoa are important food sources for many larger organisms, including insects and worms. 
Story: Two biologists studied different living creatures. Matt studied protozoa, while his friend Greg studied nematodes and insects. 
Question: Which friend studied less about predatory protozoa?
Example Output: Greg.

Example Input: Background Paragraph: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products. 
Story: Blue island and Red island were two big sister islands situated 100 miles from each other. People on Blue island used gas powered vehicles, while people on Red island used electrical vehicles. The people on Blue island presented more respiratory problems. 
Question: Which island emitted fewer harmful materials?
Example Output: Red.

Example Input: Background Paragraph: Natural resources include energy, minerals and other materials. Natural resources may be renewable or non-renewable. Non-renewable resources cannot be replaced. When they're gone, they're gone. Renewable resources can be replaced. They can supply human activities forever. Fossil fuels are crucial for modern human society. Fossil fuels are essential for transportation, industry and agriculture. Renewable energy resources tend to be clean. They emit fewer pollutants and greenhouse gases than fossil fuels. Renewable resources often have other problems. They are more costly and less efficient than fossil fuels. Still, they have many advantages. Research is going into developing renewable resources. Conservation is the best way to increase resource availability. Anyone can conserve! You and your family can. Society can. The world can. Just reduce, reuse, recycle. 
Story: A recent study compared the amount of pollution in the air of two towns, Kaya and Arcfield. Arcfield is mostly powered by solar panels. Kaya on the other hand uses fossil fuels to power most of the town. 
Question: Which town has more pollution, Kaya or Arcfield?
Example Output:
Kaya.