TASK DEFINITION: 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.
PROBLEM: Background Paragraph: Apex predators affect prey species' population dynamics and populations of other predators, both in aquatic and in terrestrial ecosystems. Non-native predatory fish, for instance, have sometimes devastated formerly dominant predators. A lake manipulation study found that when the non-native smallmouth bass was removed, lake trout, the suppressed native apex predator, diversified its prey selection and increased its trophic level. As a terrestrial example, the badger, an apex predator, predates on and also competes with the hedgehog, a mesopredator, for food such as insects, small mammals, reptiles, amphibians and ground-nesting bird's eggs. Removal of badgers (in a trial investigating bovine tuberculosis) caused hedgehog densities to more than double. Predators that exert a top-down control on organisms in their community are often considered keystone species. Humans are not considered apex predators because their diets are typically diverse, although human trophic levels increase with consumption of meat.
Story: Rob is a biologist who is interested in native species conservation. To that end, he conducted two studies, case A and case B. In case A, a non native apex predator C was introduced in formerly apex predator D's habitat. In case B, same non native apex predator C was removed from formerly apex predator D's habitat. He now needs to analyze the results of these studies.
Question: Would predator D's trophic level increase or decrease in case B than in case A?

SOLUTION: increase.

PROBLEM: Background Paragraph: During the 1670s, the Dutch tradesman Antony van Leeuwenhoek, shown in Figure below , used microscopes to observe many microbes and body cells. Leeuwenhoek developed an interest in microscopy and ground his own lenses to make simple microscopes. Leeuwenhoek was so good at making lenses that his simple microscopes were able to magnify much more clearly than the compound microscopes of his day. His microscope's increased ability to magnify over 200x is comparable to a modern compound light microscope. Compound microscopes , which are microscopes that use more than one lens, had been invented around 1595 by Zacharias Jansen, a Dutch spectacle-maker. Several people, including Robert Hooke, had built compound microscopes and were making important discoveries with them during Leeuwenhoek's time.
Story: John is interested in the history of science. He went to a science museum to learn more about microscopes. First he saw a Leeuwenhoek microscope, which was labeled as item A, then he saw a compound microscope of Leeuwenhoek's time, which was labeled as item B. At the very end of his museum tour he saw a modern compound light microscope, which was labeled as item C.
Question: Which one would have more lenses, item A or item B?

SOLUTION: item B.

PROBLEM: Background Paragraph: Once again, a mutation is the change in the DNA or RNA sequence. In multicellular organisms, mutations can be subdivided into germline mutations and somatic mutations. Germline mutations occur in the DNA of sex cells, or gametes, and are therefore potentially very serious. These mutations can be passed to the next generation. If the zygote contains the mutation, every cell in the resulting organism will have that mutation. If the mutation results in a disease phenotype, the mutation causes what is called a hereditary disease. Somatic mutations , which occur in somatic, or body, cells, cannot be passed to the next generation (offspring). Mutations present in a somatic cell of an organism will be present (by DNA replication and mitosis) in all descendants of that cell. If the mutation is present in a gene that is not used in that cell type, the mutation may have no effect. On the other hand, the mutation may lead to a serious medical condition such as cancer.
Story: The specialists studied two groups of larvae. Group L displayed all kinds of mutations while group D didn't.
Question: Which group of larvae had more germline mutations?

SOLUTION:
Group L.