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
In exocrine pancreatic cancer, the commonest tumour marker to be elevated as - 
Select and explain. 
A. CA-125, B. CEA, C. CA-15-3, D. CA-19-9
D: CA-19-9
Answer: D: CA-19-9 
Explanation: None