scientists and doctors have observed that many species of bacteria are no longer susceptible to antibiotics that were once effective

which statement explains why some bacteria species are no longer susceptible to certain antibiotics
a the bacteria learned to avoid the antibiotics
bthe bacteria modified the antibiotics to make them more effective
cthe bacteria that survived the antibiotics passed that resistance to future generations
dthe bacteria that were susceptible to the antibiotics produced a greater number of offspring

cthe bacteria that survived the antibiotics passed that resistance to future generations