What subject in prehistoric cave art was rarely shown?

a. humans
b. bulls
c. bison
d. horses
e. rhinoceroses

a. humans

a. Correct. Humans were rarely subjects in prehistoric cave art.
b. Incorrect. Bulls were a common subject for cave art.
c. Incorrect. Bison were a common subject for cave art.
d. Incorrect. Horses were a common subject for cave art.
e. Incorrect. Rhinoceroses were a common subject for cave art.