Smiling is to feeling as ________ is to ________.

A) evolution; natural selection
B) behavior; mental process
C) conscious; unconscious
D) nurture; nature

Mental Process

An internal, covert activity of the mind involving thinking, perception, memory, and reasoning.

Behavior

The way in which one acts or conducts oneself, especially towards others, influenced by the interplay of individual and environmental factors.

Natural Selection

The principle that, among the range of inherited trait variations, those that lead to increased reproduction and survival will most likely be passed on to succeeding generations.