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: Figure B above shows an important relationship between the wavelength and frequency of a wave. The top wave clearly has a shorter wavelength than the second wave. However, if you picture yourself at a stationary point watching these waves pass by, more waves of the first kind would pass by in a given amount of time. Thus the frequency of the first waves is greater than that of the second waves. Wavelength and frequency are therefore inversely related. As the wavelength of a wave increases, its frequency decreases. The equation that relates the two is.
Story: Jenna is studying waves and their related characteristics. Today, is she analyzing two different waves, wave D and wave M. Wave D has a very long wavelength, and wave M has a short wavelength. In order to verify her findings though, she is going to stand still and have both waves pass over her for the same amount of time and record the number of waves of each type that passed her.
Question: Will less wave D or wave M waves pass Jenna?
Example Output: Wave D.

Example Input: Background Paragraph: Extending the period of time over which a force acts in order to lessen the force is a common practice in design. Padding in shoes and seats allows the time to increase. The front of automobiles are designed to crumple in an accident; this increases the time the car takes to stop. Similarly, barrels of water or sand in front of abutments on the highway and airbags serve to slow down the stoppage time. These changes all serve to decrease the amount of force it takes to stop the momentum in a car crash, which consequently saves lives.
Story: Keith designs car seats. He noticed that some other car seats didn't have any padding. He marked it as case A. On the other hand, most of the seats he designed had padding. He marked it as case B. Keith needed to know pros and cons of both designs.
Question: Which case would more likely make products unsafe, case A or case B?
Example Output: case A.

Example Input: 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: Two brothers Syd and Dan went to college. Syd studied plate tectonics and mantle melting. His brother Dan got to study types of soil and pedology.
Question: Which brother studied less about the influence sediments have on mantle melting?
Example Output:
Dan.