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: Pediatrics
[{'content': 'Fetal lung maturity assessed by all except – \nSelect and explain. \nA. Measurement of α-feto protein, B. Lecithin: sphingomyelin ratio, C. Measurements of amnotic fluid creatinine, D. Phosphatidyl choline concentration in amniotic fluid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]