A Major Question Address by Comparing Monozygotic and Dizygotic Twins

Multiple Choice

A major question address by comparing monozygotic and dizygotic twins, or comparing adopted children with their adoptive and biological parents, is:

A) To what degree has natural selection influenced human evolution?
B) Does a single gene or do multiple genes influence complex behavior?
C) Are psychological disorders homozygous or heterozygous conditions?
D) To what extent do genes, the environment, and their interaction influence behavior?