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: Storing large volumes of data – When storing XML to either file or database, the volume of data a system produces can often exceed reasonable limits, with a number of detriments: the access times go up as more data is read, CPU load goes up as XML data takes more power to process, and storage costs go up. By storing XML data in Fast Infoset format, data volume may be reduced by as much as 80 percent. 
Story: Robin had a busy day storing XML. At 5 AM, he stored 220 Gigabytes to the database. At 6 AM, he stored 330 Gigabytes to the database. At 7 AM, he stored 440 Gigabytes to the database. At 8 AM, he got breakfast. At 9 AM, he stored 550 Gigabytes to the database. At 10 AM, he stored 660 Gigabytes to the database. At 11 AM, she went to sleep to finish storing XML later that day. 
Question: What time did storage costs go up:  5 AM or 11 AM?
[EX A]: 5 AM.

[EX Q]: Background Paragraph: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment. 
Story: Two sister cities were part of an air pollution study. While Prague had big air pollution problems, Belfast was eco-friendly and its inhabitants were healthy. 
Question: Which city had fewer people with an increased chance of developing lung disease?
[EX A]: Belfast.

[EX Q]: Background Paragraph: The epidermis also contains melanocytes , which are cells that produce melanin. Melanin is the brownish pigment that gives skin much of its color. Everyone has about the same number of melanocytes, but the melanocytes of people with darker skin produce more melanin. The amount of melanin produced is determined by heredity and exposure to UV light, which increases melanin output. Exposure to UV light also stimulates the skin to produce vitamin D . Because melanin blocks UV light from penetrating the skin, people with darker skin may be at greater risk of vitamin D deficiency. 
Story: Robin and Samantha are both bodybuilders preparing for a competition. Both of them are trying to change their skin complexion to help their appearances at the competition. Robin begins exposing her skin to high amounts of UV light several days a week. Samantha decides not to use any UV light and instead just uses lotion to help her skin. 
Question: Who will produce higher amounts of melanin?
[EX A]:
Robin.