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.
--------
Question: Background Paragraph: The Human Immunodeficiency Virus ( HIV ) is the virus that causes Acquired Immunodeficiency Syndrome ( AIDS ). Most researchers believe that the HIV originated in sub-Saharan Africa during the 20th century. HIV is transmitted by sexual contact and by contact with infected bodily fluids, such as blood, semen, breast milk, and vaginal secretions. It is also passed from mother to fetus. HIV is now a pandemic , with an estimated (as of 2008) 38.6 million people now living with the disease worldwide. It is estimated that AIDS has killed more than 25 million people since it was first recognized in 1981.
Story: Dean and Paul both went to volunteered in Africa. They had a blood test when they came back. Paul had been infected with the HIV virus while Dean was healthy and clean.
Question: Which friend has a virus that is transmitted by contact with infected semen?

Answer: Paul.

Question: Background Paragraph: Specific humidity (or moisture content) is the ratio of the mass of water vapor to the total mass of the moist air parcel.[13] Specific humidity is approximately equal to the mixing ratio, which is defined as the ratio of the mass of water vapor in an air parcel to the mass of dry air for the same parcel. As temperature decreases, the amount of water vapor needed to reach saturation also decreases. As the temperature of a parcel of air becomes lower it will eventually reach the point of saturation without adding or losing water mass.
Story: Tho towns located on opposite banks of a river, had a humid season, but Bend town had a cooler air at night. Bank town on the other hand, had warmer nights because it was situated on a south facing hill.
Question: Which town experienced a lower air temperature?

Answer: Bend.

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.