Cushing's Syndrome Occurs When the Body's Tissues Are Exposed to High

Cushing's syndrome occurs when the body's tissues are exposed to high levels of cortisol for too long. Many people develop Cushing's syndrome because they take steroid glucocorticoids such as prednisone for asthma, rheumatoid arthritis, lupus, and other inflammatory diseases. Other people develop Cushing's syndrome because their bodies produce too much cortisol.
-Prednisone would be most similar to which compound?

A) cortisol
B) insulin
C) TRH
D) oxytocin
E) glucagon