Social isolation involves

A) stereotypic "rocking" behavior.
B) improved social interaction.
C) an inability to connect socially.
D) the active seeking-out of others.

Social isolation refers to individuals being unable to connect with others or feeling disconnected from their social environment. Therefore, option C is the best choice. Option A is incorrect as "rocking" behavior could be associated with a variety of conditions, but it is not specific to social isolation. Option B is incorrect as isolation does not lead to improved social interaction, but rather the opposite. Similarly, option D is incorrect as those who self-isolate are not actively seeking the company of others.