A sociologist coming from this theoretical tradition would be most interested in studying the cultural significance of the universal regulation of sexuality through the incest taboo.

A) Functionalism
B) Conflict theory
C) Symbolic interactionism
D) Socialist-feminism

Functionalism is concerned with how different aspects of society contribute to the overall functioning and stability of society. The incest taboo is seen as a universal cultural norm that helps to regulate sexual behavior and prevent harmful genetic mutations, so a functionalist sociologist would be interested in studying its cultural significance. Conflict theory, symbolic interactionism, and socialist-feminism are not as directly relevant to the study of the incest taboo.