Why Is It Important to Initiate Drug Therapy Within a Certain

Why is it important to initiate drug therapy within a certain time period after exposure to a virus or onset of symptoms?

A) A virus is able to replicate at an increased speed within the first 12 hours,so it's important to try to stop it before then.
B) Severity of the infection and symptoms are reduced only when drug therapy is initiated within 1 to 2 days.
C) If the patient is given antivirals within the first 24 hours,the immune system can make enough antibodies to fight the virus.
D) Initiation of antiviral drug therapy is not as important as is getting enough rest when symptoms begin.