Which pathogen is often controlled by beneficial bacteria?
a. fungus
b. virus
c. antibiotics
d. protist

The answer to this question can be figured out by deducing the gist of the options given. A quick scan of the choices would land our eyes to antibiotics - a term we all, perhaps, have already encountered in times when we needed to fight sickness. Despite being a pathogen, antibiotics serve as "beneficial bacteria" since it helps fight off the harmful ones.

ANSWER: C. Antibiotics