Various techniques have been developed to isolate strains of bacteria carrying a particular mutation. In one, bacteria containing wild-type cells and cells of a desired mutant are grown on a medium lacking the nutrient for which the desired mutants are auxotrophic but containing the an antibiotic that only kills growing cells. In this environment, A. both wild-type and mutant cells are killed. B. both wild-type and mutant cells survive. C. wild-type cells survive; mutant cells die. D. wild-type cells die; mutant cells survive. E. only double mutants survive.
