Family Pedigree and Twin Studies Have Been Used to Look

Family pedigree and twin studies have been used to look for a genetic predisposition for unipolar depression. These studies have found:

A) a lower rate of unipolar depression among children of parents with this disorder.
B) a higher than chance rate of depression among the families of depressed patients.
C) high rates of unipolar depression among dizygotic twins but not among monozygotic twins.
D) no compelling evidence for depression among relatives of a depressed individual.