The fight-or-flight response in humans is activated by epinephrine, a hormone secreted by the glands.
pituitary
thyroid
parathyroid
adrenal

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.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

feral cats are estimated to eat tens of millions of native animals each night in australia