Which Statement Provides Evidence That Bipolar Disorder Has Much in Common

Which statement provides evidence that bipolar disorder has much in common with schizophrenia?

A) New antipsychotic drugs appear to exacerbate the manic behavior in both disorders.
B) People with bipolar disorder have relatively small hippocampi.
C) Families with a history of bipolar disorder are more likely than other families to contain individuals with schizophrenia.
D) Cognitive behavior therapy is not an effective treatment for either schizophrenia or bipolar disorder.