When the Axons of the Optic Nerve Reach the Optic

When the axons of the optic nerve reach the optic chiasm, where do they go?

A) Axons from the right eye cross to the left side, and axons from the left eye cross to the right side.
B) Axons from both eyes meet in the middle before travelling together for the rest of the pathway.
C) Axons all meet in the middle, but then return to their original sides.
D) Half of the axons cross to the opposite side and half stay on their original side.