This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
HIV was discovered in which year? 
Select and explain. 
A. 1983, B. 1979, C. 1969, D. 1990
A: 1983
Answer: A: 1983 
Explanation: Ans. (a) 1983(Ref: Robbins 9th/pg 243; 8th/pg 236)History of HIV:YearHIV linked developments1981AIDS was first recognized in the United States by U.S. Centers for Disease Control and Prevention (CDC).1983HIV isolated from a patient with lymphadenopathy (HIV 1st discovered)1984HIV demonstrated as causative agent of AIDS1985Enzyme-linked immunosorbent assay (ELISA) was developed to diagnose HIV