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: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks. 
Story: A biologist was in Australia making observations about the local species when he identified two distinct groups of butterflies. He found that one group of butterflies, group A, blended in with the dark oak trees that were common in the area. Butterflies in the other group, group B, however did not blend in as well and could easily be spotted by predators whenever they landed on the oak trees. 
Question: Will the traits belonging to the group A butterflies become more common or less common over time?
[EX A]: more common.

[EX Q]: Background Paragraph: All fluids exert pressure like the air inside a tire. The particles of fluids are constantly moving in all directions at random. As the particles move, they keep bumping into each other and into anything else in their path. These collisions cause pressure, and the pressure is exerted equally in all directions. When particles are crowded together in one part of an enclosed space, such as the air particles first entering a tire, they quickly spread out to fill all the available space. That’s because particles of fluids always move from an area of higher pressure to an area of lower pressure. This explains why air entering a tire through a tiny opening quickly fills the entire tire. 
Story: Catherine is throwing her friend a birthday party and is starting to put up decorations. She has finished hanging streamers and now she has to fill the balloons. Having never used a helium tank before, she wants to test how much to fill each balloon. 
Question: If the pressure gauge on the helium tank is high will the helium leave the tank more quickly or more slowly than if it were low?
[EX A]: more quickly.

[EX Q]: Background Paragraph: Leucism (/ˈluːsɪzəm, -kɪz-/)[1][2][3] is a condition in which there is partial loss of pigmentation in an animal resulting in white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticle, but not the eyes.[3] It is occasionally spelled leukism. Unlike albinism, it is caused by a reduction in multiple types of pigment, not just melanin. 
Story: There is a strange phenomenon going on in Siberia. Biologist noticed that 60 percent of the Siberian Tigers have leucism, and another 40 percent have albinism. They labeled the first group as group A and the latter one as group B. They need to find the reasons for this phenomenon. 
Question: Would group A have single reduced pigment or multiple reduced pigment?
[EX A]:
multiple reduced pigment.