instruction:
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: Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death. 
Story: Two teams of researchers studied different diseases. team Alpha studied people with cholesterol, while team Beta studied people with Parkinson's disease. 
Question: Which team studied more people with cholesterol and other materials deposited on the interior of the arterial wall?
answer:
Alpha.


question:
Background Paragraph: Leucism (/ˈluːsɪzəm, -kɪz-/)[1][2][3] is a condition in which there is partial loss of pigmentation in an animal resulting in white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticle, but not the eyes.[3] It is occasionally spelled leukism. Unlike albinism, it is caused by a reduction in multiple types of pigment, not just melanin. 
Story: There is a strange phenomenon going on in Siberia. Biologist noticed that 60 percent of the Siberian Tigers have leucism, and another 40 percent have albinism. They labeled the first group as group A and the latter one as group B. They need to find the reasons for this phenomenon. 
Question: Which group would have multiple types of reduced pigment?
answer:
group A.


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: Sam and Ned went on vacation, The 2 friends partied nights and spent their days on the beach. Sam started getting flu like symptoms, so he went to the doctor's office where he found out that he was infected with HIV. Ned got scared when he heard what happened, but fortunately he was OK. 
Question: Which friend didn't catch a virus that is transmitted by contact with blood?
answer:

Ned.