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
Brown tumors, compression syndromes and erythropoietin resistance is seen in: 
Select and explain. 
A. Hypothyroidism, B. Hyperthyroidism, C. Hyperparathyroidism, D. Osteoporosis
C: Hyperparathyroidism
Answer: C: Hyperparathyroidism 
Explanation: Clinical manifestations of severe hyperparathyroidism include bone pain and fragility, brown tumors, compression syndromes and erythropoietin resistance in part related to the bone marrow fibrosis.