Gary is disagreeing with a physician who states that the cause of Gary's brother's psychological illness can be traced to a physical disease. Gary's best argument against the physician is that psychopathology in the absence of any physical disease has repeatedly been observed in __________.

A) alcoholics
B) tumor victims
C) hysterics
D) syphilitics

Hysteria, or conversion disorder, is a psychological condition where a person experiences physical symptoms without any underlying physical disease. It has been observed in individuals without any physical disease and was commonly diagnosed in the past. Therefore, Gary's argument against the physician is that psychopathology in the absence of any physical disease has repeatedly been observed in hysterics.