While hiking with a friend in the Sierra Nevada mountains in California, Lenny comes face-to-face with a young bear on the trail. Lenny rapidly enters the first stage of Selye’s General Adaptation Syndrome. His brainstem initiates the release of the neurotransmitter norepinephrine, which increases his vigilance and fear. This is part of his ____

a. ?cognitive response
b. ?behavioral response
c. ?emotional response
d. ?physical response

ANSWER:
d