Using PET Scans, Researchers Found Decreased Activity in the Frontal

Using PET scans, researchers found decreased activity in the frontal lobes of the brain as well as lower activity in the right hemisphere than the left hemisphere in the brains of people with which disorder?

A) schizophrenia
B) bipolar disorder (​manic-depression)
C) ​factitious disorder (Munchausen syndrome)
D) obsessive-compulsive disorder