Answer:
C. Penicillin is mutagenic.
Step-by-step explanation:
Mutagens are agents that change genetic material. They multiply the frequency of mutations of an organism over their standard level. The peanut extract that was left as control shows this natural or standard level, but when tenths of these bacteria were put into a plate that contained penicillin, the bacteria colonies increased the frequency of mutations of these bacteria after a determined time.