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.

[Q]: Background Paragraph: Alpine tundra occurs at high enough altitude at any latitude. Portions of montane grasslands and shrublands ecoregions worldwide include alpine tundra. Large regions of alpine tundra occur in the North American Cordillera, the Alps and Pyrenees of Europe, the Himalaya and Karakoram of Asia, the Andes of South America, and the Eastern Rift mountains of Africa.Alpine tundra occupies high-mountain summits, slopes, and ridges above timberline. Aspect plays a role as well; the treeline often occurs at higher elevations on warmer equator-facing slopes. Because the alpine zone is present only on mountains, much of the landscape is rugged and broken, with rocky, snowcapped peaks, cliffs, and talus slopes, but also contains areas of gently rolling to almost flat topography.Averaging over many locations and local microclimates, the treeline rises 75 metres (245 ft) when moving 1 degree south from 70 to 50°N, and 130 metres (430 ft) per degree from 50 to 30°N. Between 30°N and 20°S, the treeline is roughly constant, between 3,500 and 4,000 metres (11,500 and 13,100 ft). 
Story: Pete and Laura were learning about Earth's vegetation. Laura read about savannas and subtropical vegetation, while Pete read about alpine tundras. 
Question: Which person read more about montane grasslands?
[A]: Pete.


[Q]: Background Paragraph: Many reactions take place in solution or in the gas phase, where the reactants are evenly dispersed throughout a homogeneous mixture. However, for reactions in which one of the reactants is a pure solid or liquid (meaning that this reactant is not already mixed together with any other reactants), reactivity only occurs at the surface, where particles of the solid or liquid reactant come into contact with particles of the other reactants. All of the molecules or ions in the interior of the pure substance will not be colliding with the other necessary reactants, so they are not really contributing to the overall rate of the reaction. However, increasing the surface area will increase the frequency of potentially reactive collisions, because more reactant particles will be in contact with the other necessary reactants. 
Story: Mike was preparing for his chemistry exam. To see the chemistry concepts in practice he conducted two tests, test A and test B. In test A he used two liquid reactants evenly dispersed, but in test B he used one liquid reactant and one solid reactant. He was surprised to see that two tests had very different results. 
Question: Which test would have higher rate of reaction, test A or test B?
[A]: test A.


[Q]: Background Paragraph: Surface temperature differences in turn cause pressure differences. A hot surface warms the air above it causing it to expand and lower the density and the resulting surface air pressure. The resulting horizontal pressure gradient moves the air from higher to lower pressure regions, creating a wind, and the Earth's rotation then causes deflection of this air flow due to the Coriolis effect. The simple systems thus formed can then display emergent behaviour to produce more complex systems and thus other weather phenomena.  Large scale examples include the Hadley cell while a smaller scale example would be coastal breezes. 
Story: In Steve's kitchen, there are two burners. Burner A is currently not turned on, and burner B is set to "medium." Steve was planning on cooking some fried eggs for lunch, but is currently distracted by an article in the newspaper that was deliver to his door. 
Question: The air above which burner is expanding?
[A]:
burner B.