What Is the Physiology Behind the Increase in Our Heart

What is the physiology behind the increase in our heart rate in fight-or-flight situations?

A) Epinephrine binds to β₂ receptors and leads to the vasodilation of the cardiac muscle arterioles.
B) Norepinephrine binds to β₂ receptors and leads to the vasoconstriction of the cardiac muscle arterioles.
C) Epinephrine binds to α₁ receptors and leads to the vasodilation of the cardiac muscle arterioles.
D) Norepinephrine binds to α₁ receptors and leads to the vasoconstriction of the cardiac muscle arterioles.
E) Epinephrine binds to α₂ receptors and leads to the vasodilation of the cardiac muscle arterioles.