Development of Drug Resistance Is Not Discouraged by

Development of drug resistance is not discouraged by

A) use of a high enough concentration of the drug to destroy any spontaneous resistant mutants that might arise.
B) use of two drugs simultaneously with the hope that each will prevent the emergence of resistance to the other.
C) avoidance of indiscriminate use of drugs.
D) using drugs appropriate for the infectious agent being treated.
E) widespread use of broad-spectrum drugs.