Explain How Using a Combination of Two Antimicrobial Drugs Helps

Explain how using a combination of two antimicrobial drugs helps prevent the development of spontaneously resistant mutants.

A) All drugs work synergistically with each other. Their combined effects are far greater than either could achieve individually. Two drugs together helps to eliminate microbes, even if they have developed spontaneous mutations that would make them resistant to the drugs.
B) It is highly unlikely that the microbe might spontaneously develop two specific mutations to resist the effects of a pair of drugs. As such, even if one drug is resisted by the microbe, the second drug will eliminate the mutated microbe, thus preventing the development of spontaneously resistant mutants overall.
C) All drugs work antagonistically with each other. Their combined effects are far greater than either could achieve individually. Two drugs together helps to eliminate microbes, even if they have developed spontaneous mutations that would make them resistant to the drugs.
D) Drugs can also select for mutations that will enhance the activity of another drug. Therefore, each of the paired drugs will help to select for spontaneous mutations that enhance the activity of the other drug in the pair.
E) Bacteria can only ever develop resistance to a single antibiotic. If more than one drug is used, the organisms will definitely become resistant to one of them but it will not become resistant to both of them. The second antibiotic will kill the organism.