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: In grassland, much of the organic matter added to the soil is from the deep, fibrous, grass root systems. By contrast, tree leaves falling on the forest floor are the principal source of soil organic matter in the forest. Another difference is the frequent occurrence in the grasslands of fires that destroy large amounts of aboveground material but stimulate even greater contributions from roots. Also, the much greater acidity under any forests inhibits the action of certain soil organisms that otherwise would mix much of the surface litter into the mineral soil. As a result, the soils under grasslands generally develop a thicker A horizon with a deeper distribution of organic matter than in comparable soils under forests, which characteristically store most of their organic matter in the forest floor (O horizon) and thin A horizon.
Story: In the Kenya-Tanzania border Kenyan grassland gradually merges into Tanzanian forest. Though they had similar soil to start with millions of years ago, today they are two different habitats. At present, Kenya has one of the largest contiguous grassland in Africa. On the other hand, Tanzania boasts one of the largest forest cover in Africa.
Question: Which place would have thinner "A horizon", Kenya or Tanzania?
[EX A]: Tanzania.

[EX Q]: Background Paragraph: Hypertension , which is also called "high blood pressure," occurs when a person's blood pressure is always high. Hypertension is said to be present when a person's systolic blood pressure is always 140 or higher, and/or if the person's diastolic blood pressure is always 90 or higher. Having hypertension increases a person's chance for developing heart disease, having a stroke, or suffering from other serious cardiovascular diseases. Hypertension often does not have any symptoms, so a person may not know that he or she has high blood pressure. For this reason, hypertension is often called the "silent killer." Treatments for hypertension include diet changes, exercise, and medication. Foods thought to lower blood pressure include skim milk, spinach, beans, bananas and dark chocolate.
Story: At a doctor's office, two women are having their annual physical done. Jessie goes in first and is told that that she should go see a dermatologist about the skin issues she is having. The doctor then sees Martha who is having a pain in her right arm and who also has hypertension. The doctor talks to Martha about her issues and then heads home for the day.
Question: Is Jessie's risk for cardiovascular diseases higher or lower than Martha's?
[EX A]: lower.

[EX Q]: Background Paragraph: Energy is passed up a food chain or web from lower to higher trophic levels. However, only about 10 percent of the energy at one level is passed up the next level. This is represented by the ecological pyramid in Figure below . The other 90 percent of energy at each trophic level is used for metabolic processes or given off to the environment as heat. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. There isn't enough energy left to support additional levels. It also explains why ecosystems need a constant input of energy.
Story: An island in the Pacific ocean has a strange an compact ecosystem. There are only 4 species of living organism on it. There are plants, Insects, birds, cats. Because of this there is a very specific food chain on this island. Any new species added to it has cause the population of all other species to decrease. This is because when a new species is added it causes the others to not have enough food as they all feed on each other. The insects eat the plants, the birds eat the insects and the cats eat the birds. When a species of wolf that eats the cats was added the plants began to die off because the wolves outlived the cats so the plants could not get the energy in time to regrow before the insects would eat them. Because of this the insects would die, then the birds then the cats. because the energy source for each species was being consumed faster than it could be produced.
Question: Will the insect population decreasing cause the available energy to the bird population to increase or decrease?
[EX A]:
decrease.