Which of the following statements BEST describes an opportunistic infection (OI)?
A.
OIs are common only to people with healthy immune systems.
B.
OIs are more frequent in the earlier stages of HIV.
C.
OIs are the common cause of death of people with HIV/AIDS.
D.
OIs can be deadly to perfectly healthy people.

Please select the best answer from the choices provided.

A
B
C
D