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
[{'content': 'All of the following statements are true about tumour markers except \nSelect and explain. \nA. screening of a cancer, B. follow up of a cancer patient, C. confirmation of cancer, D. for knowing about recurrence', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]