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.
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Question: Background Paragraph: Although some lipids in the diet are essential, excess dietary lipids can be harmful. Because lipids are very high in energy, eating too many may lead to unhealthy weight gain. A high-fat diet may also increase lipid levels in the blood. This, in turn, can increase the risk for health problems such as cardiovascular disease. The dietary lipids of most concern are saturated fatty acids, trans fats, and cholesterol. For example, cholesterol is the lipid mainly responsible for narrowing arteries and causing the disease atherosclerosis. 
Story: Two groups of people were part of a science study. Group A ate lots of fats(lipids), while Group B  had a more balanced diet with few fats. Group A gained a lot of weight over the course of the 6 month study. 
Question: Which group had increased lipid levels in the blood?

Answer: Group A.


Question: Background Paragraph: As for the public health or food safety concern, organic foods are intended to be healthy, free of contaminations and free from agents that could cause human diseases. Organic milk is meant to have no chemical residues to consumers, and the restrictions on the use of antibiotics and chemicals in organic food production has the purpose to accomplish this goal. Although dairy cows in both organic and conventional farming practices can be exposed to pathogens, it has been shown that, because antibiotics are not permitted as a preventative measure in organic practices, there are far fewer antibiotic resistant pathogens on organic farms. This dramatically increases the efficacy of antibiotics when/if they are necessary. 
Story: Two farms were growing food for several nearby cities. Vole farm grew organic produce and produced organic milk, while Anthill farm did not possess the USDA organic certification. 
Question: Which farm produces more milk with no chemical residues?

Answer: Vole.


Question: Background Paragraph: Blood vessels help regulate body processes by either constricting (becoming narrower) or dilating (becoming wider). These actions occur in response to signals from the autonomic nervous system or the endocrine system. Constriction occurs when the muscular walls of blood vessels contract. This reduces the amount of blood that can flow through the vessels (see Figure below ). Dilation occurs when the walls relax. This increases blood flows through the vessels. 
Story: Greg is a physician working for the city hospital. Today he is seeing two patients, patient A and patient B. He noticed that patient A's blood vessels are constricted, but blood vessels of patient B are dilated. He needs to prescribe medicine according to his observation. 
Question: Which patient would have less blood passing through the vessels, patient A or patient B?

Answer:
patient A.