Freud is the first to describe the : that the mind could contain information of which it is unaware, but by which it is still affected.
a. catharsis
b. unconscious
c. hysteria
d. operant conditioning

b. unconscious        

Explanation:

Sigmund Freud has discovered the three distinct levels of an individual's mind including conscious, unconscious, and the subconscious in his psychoanalytic theory.

Unconscious: In psychology, the term unconscious is defined as a reservoir of thoughts, memories, urges, and feelings that are outside an individual's conscious awareness yet the person gets affected with the same. Freud argued that most of the components of an individual's unconscious mind are unpleasant like feelings of conflict, pain, and anxiety, etc.

well, there are a lot of places we get information about earth from. like science classes, websites, books, newspapers, etc.

answer; participant observation method;