Research suggests that adopted children who have two biological parents with bipolar disorder have:

a. an increased likelihood of being diagnosed with bipolar disorder themselves, but only if they have extended contact with their biological parents
b. a decreased likelihood of being diagnosed with bipolar disorder themselves, but only if they have extended contact with their biological parents
c. an increased likelihood of being diagnosed with bipolar disorder themselves, even if they've had little or no contact with their biological parents
d. a decreased likelihood of being diagnosed with bipolar disorder, but an increased likelihood of being diagnosed with other psychological disorders

C