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.
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Question: Background Paragraph: The ionization energies of the representative elements generally decrease from top to bottom within a group. This trend is explained by the increase in size of the atoms within a group. The valence electron that is being removed is further from the nucleus in the case of a larger atom. The attractive force between the valence electron and the nucleus weakens as the distance between them increases and as the shielding effect increases, resulting in a lower ionization energy for the larger atoms within a group. Although the nucl. 
Story: Jeremy is studying the periodic table in preparation for a chemistry test next week. Today he is focusing on the elements that all belong to the alkali metals group. He is especially focused on learning about lithium, which is at the top of the group, and cesium, which is at the bottom of the alkali metals group. 
Question: Which element is larger?

Answer: cesium.


Question: Background Paragraph: In exercises such as weight lifting, skeletal muscle contracts against a resisting force (see Figure below ). Using skeletal muscle in this way increases its size and strength. In exercises such as running, the cardiac muscle contracts faster and the heart pumps more blood. Using cardiac muscle in this way increases its strength and efficiency. Continued exercise is necessary to maintain bigger, stronger muscles. If you don’t use a muscle, it will get smaller and weaker—so use it or lose it. 
Story: Michael has become bored with his passive life style, and has decided to take up weight lifting as a hobby. He begins to exercise with weights several times a week. Michael's brother, Robert, isn't as motivated as Michael though. Robert decides to continue being mostly inactive and only exercises with weights every couple of months. 
Question: Who will increase the strength of their muscles less?

Answer: Robert.


Question: 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 thicker "A horizon", Kenya or Tanzania?

Answer:
Kenya.