The researcher inoculates the test population of bacteria onto glucose salts agar containing penicillin and also on nutrient agar containing penicillin. she counts 25 colonies on the glucose salts plate lacking histamine and 32 colonies on the nutrient agar. which of the following statements is true? a. the colonies on both plates contain penicillin-resistant mutants. b. the glucose salts plate contains some mutants. c. the bacteria on the glucose salts medium are mutants while the bacteria on the nutrient agar are wild type. d. the bacteria growing on the nutrient agar are mutants while those growing on the glucose salts medium are wild type. e. the bacteria that failed to grow on the glucose salts medium are double mutants.