TASK DEFINITION: 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.
PROBLEM: 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: Matt and his brother Jesse are twins. They look almost identical. If it weren't for the fact that Jesse has a slightly darker skin complexion you wouldn't be able to tell them apart. In fact one year Matt was out in the sun for a long time and picked up a bit of a tan so they actually did look exactly alike. 
Question: Will an increase in the amount of melanin produced make a person skin darker or lighter?

SOLUTION: darker.

PROBLEM: Background Paragraph: The primary role of red blood cells in the circulatory system is to transport oxygen to the tissues. The actual carrier of oxygen molecules is the protein hemoglobin, which binds to the oxygen and moves it throughout the body, releasing it in areas where the concentration of dissolved oxygen is low. A certain mutation in the gene for hemoglobin causes a slight change in the structure of this crucial protein, resulting in a disease called sickle-cell anemia. For people with this mutation, the hemoglobin produced by their red blood cells has a tendency to clump together, distorting the shape of the red blood cells and giving rise to the crescent-shaped cells seen above. By understanding the changes in structure that are the underlying cause of this disease, we have developed various ways to treat and manage this illness. 
Story: Dan had two children: Karen which had sickle-cell anemia, and his son Bob, which was healthy. 
Question: Which child has a hemoglobin that clumps together?

SOLUTION: Karen.

PROBLEM: Background Paragraph: Alberta's electrical demand varies throughout the day and across the seasons. When individuals are fixing supper and using home appliances, demand for power goes up, as it does during heat waves and cold snaps. It tapers off during spring and fall. Like other mechanical devices, generators fail from time to time. If they are wind-powered, their output varies with the wind. 
Story: Carl is in charge of a power generation station in Alberta. He is tasked with turning on or off certain generators in instances of high or low demand (High demand would require more generators to be turned on, and low turned off). There are various occasions that Carl has to be vigilant for, such as various times of the day; early morning, dinner time, late night. Weather conditions also play a roll, such as; colder weather, hot weather, or moderate weather. He also must be aware of wind conditions, as some of the power is garnered from wind power. 
Question: Would Carl be more likely to have to use more generators on a hot day or a moderate day?

SOLUTION:
hot day.