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: Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases. With more surfaces exposed, there are more places for chemical weathering to occur ( Figure below ). Let’s say you wanted to make some hot chocolate on a cold day. It would be hard to get a big chunk of chocolate to dissolve in your milk or hot water. Maybe you could make hot chocolate from some smaller pieces like chocolate chips, but it is much easier to add a powder to your milk. This is because the smaller the pieces are, the more surface area they have. Smaller pieces dissolve more easily. 
Story: Rocks commonly found in Beijing are often found spread out in smaller pieces, whereas rocks in Montreal typically remain large in size and don't break apart as much. Both Beijing and Montreal are expected to experience bouts of acid rain in the upcoming weeks. 
Question: Which area's rocks will have higher rates of chemical weathering caused by the acid rain?
[A]: Beijing.


[Q]: Background Paragraph: While people have been able to prevent certain viral diseases by vaccinations for many hundreds of years, the development of antiviral drugs to treat viral diseases is a relatively recent development. Antiviral drugs are medications used specifically for treating the symptoms of viral infections. The first antiviral drug was interferon , a substance that is naturally produced by certain immune cells when an infection is detected. Over the past twenty years the development of antiretroviral drugs (also known as antiretroviral therapy, or ART) has increased rapidly. This has been driven by the AIDS epidemic. 
Story: The Doctor studied two teams of people. Team N had no viral infections, while Team W had many people with HIV among its members. Obviously, team N had fewer health issues. 
Question: Which team had fewer people receiving vaccinations for viral diseases?
[A]: team N.


[Q]: Background Paragraph: Carbon monoxide is used in modified atmosphere packaging systems in the US, mainly with fresh meat products such as beef, pork, and fish to keep them looking fresh. The carbon monoxide combines with myoglobin to form carboxymyoglobin, a bright-cherry-red pigment. Carboxymyoglobin is more stable than the oxygenated form of myoglobin, oxymyoglobin, which can become oxidized to the brown pigment metmyoglobin. This stable red color can persist much longer than in normally packaged meat. Typical levels of carbon monoxide used in the facilities that use this process are between 0.4% to 0.5%. 
Story: Mike went to his local grocery store. He noticed that meats had two different packaging, product A and product B. When he looked closely, he found that in product A packaging carbon monoxide was used, but in product B carbon monoxide was not used. He asked the store clerk what difference it made. 
Question: Which product would less likely look fresher, product A or product B?
[A]:
product B.