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 is elevated in: 
Select and explain. 
A. Primary biliary cirrhosis, B. Hypophosphatemia, C. Hyperphosphatemia, D. Hepatatis-A
A: Primary biliary cirrhosis
Answer: A: Primary biliary cirrhosis 
Explanation: Primary biliary cirrhosis