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: Surgery
Diagnostic tumor marker for medullary thyroid cancer : 
Select and explain. 
A. BRAF, B. VMA, C. Calcitonin, D. Melatonin - 1
C: Calcitonin
Answer: C: Calcitonin 
Explanation: Medullary carcinoma of thyroid arises from parafolicular or C - cell which secrete "calcitonin".