How Do Sociologists Define Race

How do sociologists define race?

A) using a scheme that involves three racial categories: Caucasoid, Negroid, and Mongoloid.
B) as any group with a shared cultural heritage
C) as a self-conscious identification with a group that most closely resembles one's culture
D) as a category of people that is formed when there is widespread agreement on the identification of a group and the definition of the group as a "race"