The correct option is D The time-lag between the infection and appearance of AIDS symptoms may vary form week to month.
Human immunodeficiency virus infection or acquired immune deficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV), an RNA-containing virus. It is transmitted through body fluid by sexual contact, blood transfusion and across the placenta during pregnancy. When it attacks the host organism it destroys the immune cells, particularly, T cells because virus uses them for their multiplication. Following initial infection, a person may experience a brief period of influenza-like illness. This is typically followed by a prolonged period without symptoms. As the infection progresses, it interferes more and more with the immune system, making the person much more susceptible to common infections like tuberculosis, as well as opportunistic infections and tumors that do not usually affect people who have working immune systems. Thus, the correct answer is option D.