PEP Is Initiated Only If Exposure Is Severe, and the Source

PEP is initiated only if exposure is severe, and the source of fluid is known or strongly suspected to contain HIV? What is the rationale for this?

A) The cost and anxiety associated with taking the drugs are high.
B) There is not enough research supporting this treatment.
C) The cost of the drugs is high, and there are many ethical issues surrounding their use.
D) The cost of the drugs is high, and there are many adverse effects.