The American Physiologist Walter Cannon

The American physiologist Walter Cannon:

A) described the fight-or-flight response, which involves the sympathetic nervous system and the endocrine system.
B) demonstrated that the immune system could be classically conditioned, a finding that helped establish the field of psychoneuroimmunology.
C) described the three-stage response to prolonged stress called the general adaptation syndrome.
D) conducted research on explanatory style and the role it plays in stress, health, and illness.