Which Autonomic Receptor Mediates Secretion of Epinephrine by the Adrenal $\alpha$

Which autonomic receptor mediates secretion of epinephrine by the adrenal medulla?

A) Adrenergic $\alpha$ receptors
B) Adrenergic $\beta_{1}$ receptors
C) Adrenergic $\beta_{2}$ receptors
D) Cholinergic muscarinic receptors
E) Cholinergic nicotinic receptors