This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
HIV which is found in West Africans is? 
Select and explain. 
A. HIV 1, B. HIV 2, C. HIV 3, D. HIV 4
B: HIV 2
Answer: B: HIV 2 
Explanation: HIV 2 REF: Harrison's Internal Medicine > Chapter The four recognized human retroviruses lymphotropic viruses (HTLV)-I and HTLV-II, immunodeficiency viruses, HIV-1 and HIV-indirectly. The most common cause of HIV disease throughout the world, and ceainly in the United States, is HIV-1, which comprises several subtypes with different geographic distributions (see below). HIV-2 was first identified in 1986 in West African patients and was originally confined to West Africa. However, a number of cases that can be traced to West Africa or to sexual contacts with West Africans have been identified throughout the world. Both HIV-1 and HIV-2 are zoonotic infections