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: The example of someone having a positive experience with a drug is easy to see how drug dependence and the law of effect works. The tolerance for a drug goes up as one continues to use it after having a positive experience with a certain amount the first time.[38] It will take more and more to get that same feeling. This is when the controlled substance in an experiment would have to be modified and the experiment would really begin. The law of work for psychologist B. F. Skinner almost half a century later on the principles of operant conditioning, "a learning process by which the effect, or consequence, of a response influences the future rate of production of that response.[39]. 
Story: The cocaine club met to discuss their experiences. They all said they always had a great experience using cocaine and used the same amount each time. They told how many times they used cocaine. Mary used it 2 times, Patricia used it 3 times, Linda used it 5 times, Barbara used it 10 times, Elizabeth used it 15 times, Jennifer used it 20 times, and Maria used it 30 times. 
Question: Who has a higher tolerance for cocaine: Jennifer or Linda?
[EX A]: Jennifer.

[EX Q]: Background Paragraph: Saturated hydrocarbons are given the general name of alkanes . The name of specific alkanes always ends in – ane . The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table below . The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures. 
Story: Two students studied chemistry. Nate studied alkanes, and Ben studied noble gasses. They both got an A later on. 
Question: Which student learned more about methane?
[EX A]: Nate.

[EX Q]: Background Paragraph: Precipitation in grasslands is equal to or less than evapotranspiration and causes soil development to operate in relative drought. Leaching and migration of weathering products is therefore decreased. Large amounts of evaporation causes buildup of calcium (Ca) and other large cations flocculate clay minerals and fulvic acids in the upper soil profile. Impermeable clay limits downward percolation of water and fulvic acids, reducing chemical weathering and podzolization. The depth to the maximum concentration of clay increases in areas of increased precipitation and leaching. When leaching is decreased, the Ca precipitates as calcite (CaCO3) in the lower soil levels, a layer known as caliche. 
Story: Monsoon plays a big role in shaping local climates. In some places of the Horn of Africa monsoon causes heavy rainfall. But across the Red Sea the Arabian Peninsula mostly misses the monsoon. As a result, they have minimal rainfall throughout the year. 
Question: Would the concentration of clay be deeper or shallower in Horn of Africa than in Arabian Peninsula?
[EX A]:
deeper.