A.J.'s behavior is characterized by markedly impaired motor activity that slows to a stupor but then switches abruptly into an agitated phase. He sometimes "freezes" in bizarre, uncomfortable-looking postures that he maintains for hours, even as his limbs become stiff and swollen. He acts mute during these periods and displays waxy flexibility. He is best described as displaying __________ behaviors.

A. paranoid
B. disorganized
C. catatonic
D. undifferentiated

Answer: C