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: Orthopaedics
[{'content': 'Which of the following is a persistant biochemical marker of rickets - \nSelect and explain. \nA. S.Ca++, B. S Alkaline phosphatase, C. S. Acid phosphate, D. S. phosphate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Serum alkaline phosphatase is a consistent marker and is raised in all types of rickets.', 'role': 'assistant'}]