The sexually transmissible disease gonorrhea has become increasingly resistant to treatment with antibiotics. What is the most likely scientific explanation?
a) The gonorrhea bacteria learned to avoid antibiotics
b) The gonorrhea bacteria changed their genes when they sensed antibiotics
c) Antibiotic-sensitive gonorrhea bacteria died out, but antibiotic-resistant gonorrhea bacteria have flourished and persisted
d) The antibiotic increased the mutation rate in the gonorrhea bacteria
e) Both b and d