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
[{'content': 'Which of the following can be used as tumor marker in pancreatic carcinoma? \nSelect and explain. \nA. CA-125, B. CA 27-29, C. CA 19-9, D. CA 15-3', 'role': 'user'}, {'content': 'Answer: C \nExplanation: CA 19-9 is a tumor marker for pancreatic as well as colon cancers.', 'role': 'assistant'}]