Which of the following describes a tropic hormone?

• A. Insulin is a hormone that causes the body to produce glycogen, removing sugar from the bloodstream.
• B. Thyroid stimulating hormone signals the thyroid gland to release the hormone thyroxin.
• C. Epinephrine is a hormone that leads to many different physiological changes in many different tissues.
• D. Estrogen is a lipid soluble hormone, and therefore can pass through the cell membrane.