Under Which of the Following Conditions Would Resistance to a Specific

Under which of the following conditions would resistance to a specific antibiotic most likely evolve?

A) when the antibiotic is not commonly used
B) when the antibiotic is routinely used, even in inappropriate situations
C) when the antibiotic is used, but only in carefully controlled and appropriate situations
D) when the use of the antibiotic is suddenly curtailed
E) when several antibiotics, including the specific antibiotic under consideration, are used together