Mr. Harrison came to the office last week because he was confused and concerned by recent physical developments. His hands and feet seem to be getting bigger, and he is developing gaps between his teeth. He is here today for a follow-up visit, and the physician informed him that he has a pituitary tumor that needs to be removed. Mr. Harrison's symptoms are typical of which of the following disorders?

A) Cushing's syndrome
B) Addison's disease
C) Acromegaly
D) Hyperthyroidism