Evidence for the evolution of antibiotic resistance in bacteria has been evaluated ________.

A) in populations of bacteria within individual patients
B) in studies comparing newly diagnosed patients v. patients who have relapsed after antibiotic treatment
C) in studies comparing the fraction of patients with resistant bacteria and society-wide use of antibiotics
D) in all of the above examples
E) in no empirical studies; there is no evidence that antibiotics act as a selective agent