Unconscious thought is generally due to and conscious thought is gen-erally due to a. superego functioning; id functioning b. secondary process thinking; primary process thinking c. primary process thinking; secondary process thinking d. regression; repression

Unconscious thought is generally due to primary process thinking, and conscious thought is generally due to secondary process thinking. Primary process thinking pertains to one's formation of a mental image about his/her desired object in order to satisfy his/her desire for the object. On the other hand, secondary process thinking is when one thinks logically as influenced by his/her ego and some environmental factors. 

The answer is letter C.
Unconscious thought is generally due to primary process thinking, and conscious thought is generally due to secondary process thinking.
Primary process thinking is the unconscious thought of the id, which uses symbols and metaphors, while the secondary process thinking is the conscious mental and logical thinking that manage by the ego and influenced by environmental demands.