An adolescent is brought to therapy by her mother who says the girl has recently become "another person." She says her daughter used to be easy-going and easy to get along with and was well-liked at school by her peers and teachers. However, now her daughter is constantly irritable, is smoking and drinking, and has started having trouble at school. When the therapist interviews the girl, he learns that she is engaging in high-risk sexual behavior, but the girl feels that nothing bad can ever happen to her. Based on these symptoms, the best diagnosis is:_______
a. ADHD.
b. Conduct Disorder.
c. Bipolar I Disorder.
d. Bipolar II Disorder.