This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetal Assessment, Subject name: Gynaecology & Obstetrics
[{'content': "Which does not indicate fetal lung maturity' - \nSelect and explain. \nA. Reactive NST, B. Gestation 37 weeks, C. Presence of phosphatidyl choline, D. L/S ratio", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Reactive NST", 'role': 'assistant'}]