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: Unknown
[{'content': "Diagnostic serum markers in Down's syndrome are all except - \nSelect and explain. \nA. Free oestriol, B. Alpha feto protein, C. HCG, D. Progesterone", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans-D', 'role': 'assistant'}]