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: Pathology
Serum alkaline phosphatase level is reduced in: 
Select and explain. 
A. Paget's disease., B. Hyperparathyroidism., C. Hypothyroidism., D. Fibrous dysplasia.
C: Hypothyroidism.
Answer: C: Hypothyroidism. 
Explanation: None