A synapomorphy is a shared apomorphy that distinguishes a clade from other organisms. A clade also known as monophyletic group, is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single "branch" on the "tree of life".
The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.
The answer is C. Your eyes respond the the amount of light going into your eyes so they get smaller when exposed to more light and dilate when the amount of light is lessened