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': 'A 70 years old man with prostate cancer was given radiotherapy. The recurrence of the cancer is monitored biochemically by: \nSelect and explain. \nA. Androgens only, B. Prostate specific antigen and carcinoembryonic antigen, C. Prostate specific antigen only, D. ALP and CEA', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. c. Prostate specific antigen only', 'role': 'assistant'}]