Question

AIDS is caused by HIV that primarily infects
A. All lymphocytes
B. Activator B cells
C. T-4 lymphocytes
D. Cytotoxic T cells

Answer 1

Hint: AIDS is Acquired immunodeficiency syndrome which is caused by an immune attacking virus called HIV or human immunodeficiency virus. The virus attacks the immune system of the host which leaves the host susceptible to various other diseases. Very specifically the CD4$+$ cells are affected.

Complete answer:
AIDS is a potentially life-threatening disease which is caused by HIV. It primarily damages the immune system of the infected person. The virus interferes with the host body’s ability to fight diseases or infections. It is a sexually transmitted disease and hence is classified as an STD. it can also be transmitted from an infected mother to her child by breastfeeding or infected blood during pregnancy.
The disease progresses slowly without symptoms for years weakening the immune system of the host. It is not detectable until other acute infections easily affect the vulnerable host. The primary target of the virus is CD4$+$ or T-4 helper cells that promote macrophages' ability to destroy the virus. The T-4 helper lymphocytes also play an important role in the activation of B cells that further produces antibodies to destroy virus antigen. T-4 helper lymphocytes have an important role in adaptive immunity and help to activate the cytotoxic T cells. As the target of HIV is the immune system the real threat is from other infections to which the host becomes vulnerable.

So, option C) is the correct answer.

Note: There is still no cure for AIDS but there are preventive measures like avoiding multiple sex partners, avoiding infected needles, etc. There are medications for slowing the disease progression. All these medications target making the immune system strong.