Choose the Pair That Contains the Two Correct Ways to Cause

Multiple Choice

Choose the pair that contains the two correct ways to cause an increase in the firing rate of pacemaker cells of the heart.

A) Stimulating the parasympathetic nerve to the heart; applying norepinephrine to pacemaker cells
B) Applying acetylcholine to pacemaker cells; stimulating the parasympathetic nerve to the heart
C) Damaging the sympathetic nerve to the heart; applying norepinephrine to pacemaker cells
D) Stimulating the sympathetic nerve to the heart; applying norepinephrine to pacemaker cells
E) Damaging the sympathetic nerve to the heart; applying acetylcholine to pacemaker cells