Our self-concept is defined as:

A) a schema we have about ourselves.
B) the category of person into which we place ourselves.
C) the impression we have of our own body.
D) a human ability to recognize that other people are all unique selves.

Our self-concept is a mental representation of ourselves, which includes our beliefs, attitudes, and values. It is essentially a schema or mental framework that we have about ourselves. The other options do not fully capture the complexity and breadth of our self-concept.