The optic nerve is composed of axon fibers from

A) ganglion cells.
B) both cones and rods.
C) cones.
D) rods.

The optic nerve is composed of axons from ganglion cells, which transmit visual information from the retina to the brain. While cones and rods are responsible for capturing and processing visual information, it is the ganglion cells that send this information through the optic nerve to be interpreted by the brain. Therefore, choice A is the best answer. Choices B, C, and D are incorrect as they suggest that the optic nerve contains axons from cones or rods, which is not the case.