Question

The fight-or-flight response in humans is activated by epinephrine, a hormone secreted by the _____ glands.

Answer 1

The sympathetic nervous system. The hypothalamus, in close association with the limbic system of the brain. The two main chemicals invoved here are the neurotransmitter "norepinephrine" (noradrenaline) and the hormone "epinephrine" (adrenaline).
So I would say D

Answer 2

The correct answer is adrenal

Adrenal glands are also called suprarenal glands which are located on the kidneys. They produce various hormones including epinephrine (adrenaline). Adrenaline is secreted when a person is under a fight-or-flight. This hormone quickly responds to the emergent situation or threat by increasing heart rate, slowing blood flow to muscle cells and changes other autonomic nervous functions, which gives energy and strength to fight any emergency.