Based on the Research into Genetic Factors, the Risk of Having

Based on the research into genetic factors, the risk of having schizophrenia is

A) unrelated to the presence of schizophrenia in family members.
B) greatest among people when a fraternal twin has suffered from the disorder.
C) greatest among people when both parents have suffered from the disorder.
D) greatest when no one in the family has suffered from the disorder.