What Indication of a Genetic Connection Between Schizophrenia and Bipolar

What indication of a genetic connection between schizophrenia and bipolar disorder is mentioned in the textbook?

A) Family members of people with schizophrenia never evidence bipolar disorder
B) Family member of people with schizophrenia are at elevated risk of having bipolar disorder
C) Sisters of schizophrenic patients have a 30 percent likelihood of having bipolar disorder.
D) Sisters of people with bipolar disorder have a 30 percent likelihood of being schizophrenic.