Why is Combination Drug Therapy Less Likely to Lead to Resistance

Question

Why is combination drug therapy less likely to lead to resistance than single drug therapy?
A) In the presence of multiple drugs, the mutation rate of HIV decreases.
B) The drugs improve the immune system so that it's better able to find and remove virus particles.
C) The likelihood of one virus spontaneously mutating to be resistant to three different drugs is extremely small.
D) There are fewer side effects associated with combination drug therapy, and the appearance of resistance is directly proportional to the severity of side effects.

Accepted Answer

Combination drug therapy makes it extremely unlikely for a virus to spontaneously mutate to be resistant to three different drugs at the same time. This is because the probability of such a mutation occurring is very low. Therefore, the use of multiple drugs reduces the likelihood of the emergence of resistant strains.