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: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. 
Story: Jimbo and Jedd are both farmers who have lakes and water wells downstream from their farms. Jimbo's products have been in high demand recently, so he has started to use very high amounts of fertilizers on his farms. Jedd has recently decreased the amount of fertilizer he uses because his products aren't wanted as much by the people in his town. 
Question: Who will be less likely to contaminate their respective water wells?
[EX A]: Jedd.

[EX Q]: Background Paragraph: A baby is born with zones of cartilage in its bones that allow growth of the bones. These areas, called growth plates , allow the bones to grow longer as the child grows. By the time the child reaches an age of about 18 to 25 years, all of the cartilage in the growth plate has been replaced by bone. This stops the bone from growing any longer. Even though bones stop growing in length in early adulthood, they can continue to increase in thickness throughout life. This thickening occurs in response to strain from increased muscle activity and from weight-lifting exercises. 
Story: Two brothers, Tom, aged 26, and Paul, aged 16 were into sports. Tom started weight-lifting to gain more muscle mass. Three years later he was 20-25 lbs. heavier. Paul started track and field, he liked running. 
Question: Which brother had thicker bones after three years?
[EX A]: Tom.

[EX Q]: Background Paragraph: Mantle melting can come about three ways: (1) when the temperature rises, (2) if the pressure lowers (which lowers the melting point), and (3) if water is added, which lowers the melting point. Two of these (1 and 3) might explain why there are volcanoes at convergent plate boundaries: the temperature of the subducting plate increases as it sinks into the hot mantle (1). Sediments lying on top of the subducting plate contain water. As the sediments subduct, the water rises into the overlying mantle material. This lowers the melting temperature of the mantle (3). When the mantle above the subducting plate melts, volcanoes form above it. This leads to volcanoes in an island arc or continental arc. 
Story: Ben and Mike both studied earthquakes, while Mike was more interested specifically in mantle melting and related phenomena. 
Question: Which person studied less about volcanoes at convergent plate boundaries?
[EX A]:
Ben.