A 40-year-old woman with hypertension comes to the physician because of excessive thirst, excessive urination, constipation, and a depressed mood. Her medications include hydrochlorothiazide. Laboratory studies show a serum calcium level of 11.0 mg/dL. 
Which of the following underlying disorders is most likely?: (A) Medullary carcinoma of the thyroid, (B) Multiple myeloma, (C) Parathyroid adenoma, (D) Porphyria
Answer is C. None