Using the "Core Features" of Abnormal Behavior in Identifying Mental

Using the "core features" of abnormal behavior in identifying mental disorders, how is abnormal behavior best defined?

A) behavior that makes daily life more difficult and which indicates a loss of control
B) behavior which causes a person extreme personal discomfort and is socially non-conforming
C) behavior which is illegal and/or persistently non-conformist
D) behavior that is statistically different from the average of the general population