Final answer:
The optic nerve's primary function is to transmit visual information from the retina to the brain, enabling us to process and understand what we see.Thus the correct option is 4.
Step-by-step explanation:
The main function of the optic nerve is to transmit visual information from the retina to the brain. The optic nerve consists of axons from the retinal ganglion cells, which carry signals related to form, movement, depth, brightness, color, and fine detail. These signals are then processed by various parts of the brain, including the superior colliculi for eye movement coordination and the suprachiasmatic nucleus for circadian rhythm regulation. It is important to note that the optic nerve is solely responsible for conveying visual information and does not control the movement of the eye or eyelid, nor does it sense touch on the skin surrounding the eye.