This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
In hyperparathyroidism, all are seen except 
Select and explain. 
A. Osteopetrosis, B. Osteoporosis, C. Cysts, D. Brown tumor
A: Osteopetrosis
Answer: A: Osteopetrosis 
Explanation: Parathyroid hormone (PTH), also called parathormone or parathyrin, is a hormone secreted by .... (most, 60-70%, of it in the proximal tubule), except in the thin segment of the loop of Henle. .... while secondary hyperparathyroidism is an appropriately high PTH level seen as a physiological .... "A mouse for all reasons".