200
For many years, penicillin was used to fight bacterial infections. However, penicillin is no longer an effective treatment for some bacterial infections. Which statement explains this change?
A. Some bacteria had mutations that prevented penicillin from affecting them, and they reproduced.
B. Some bacteria multiplied rapidly and overwhelmed the penicillin.
C. Some bacteria used the penicillin as a source of energy.
D. Some bacteria adapted to their environment and they destroyed the penicillin.
A. Some bacteria had mutations that prevented penicillin from affecting them, and they reproduced.