In the past, African elephants have been hunted for their tusks. Over time, the number of tuskless elephants has increased while the number of elephants with tusks has decreased. What is the most likely explanation for the increase in the number of tuskless elephants? a

Fewer elephants with tusks survived to reproduce.

b

The gene for tusks has become recessive over time.

c

The hunting of elephants resulted in genetic mutation of the tusk gene.

d

Elephants began to lose their tusks because of climate changes.