Carina Is 50 Years Old, and She Never Seems to Be

Carina is 50 years old, and she never seems to be on an even keel. Some days she is excited and happy, other days she is sad and withdrawn. Her symptoms seem fairly mild, but she has had mood swings of this type since she was in her early 20s. Carina's symptoms are MOST consistent with those seen in

A) cyclothymic disorder.
B) dysthymic disorder.
C) undifferentiated schizophrenia.
D) dissociative identity disorder.