Deficient social interaction and an impaired understanding of others' states of mind is most characteristic of

A) autism.
B) menarche.
C) crystallized intelligence.
D) object permanence.

Deficient social interaction and impaired understanding of others' states of mind are hallmark symptoms of autism spectrum disorder. Menarche refers to the onset of menstruation and is not related to social interaction or understanding of others. Crystallized intelligence refers to acquired knowledge and skills through experience and education, and object permanence is the understanding that objects continue to exist even when they are not in sight, neither of which are related to deficient social interaction and impaired understanding of others.