Bronchodilation Occurs When Circulating Catecholamines Interact with Which of the Following

Bronchodilation occurs when circulating catecholamines interact with which of the following sympathetic nervous system receptors?

A) $\beta$ ₁ receptors only
B) $\beta$ ₂ receptors only
C) $\beta$ ₁ and $\beta$ ₂ receptors
D) $\beta$ ₁, $\beta$ ₂,and $\alpha$ receptors