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: Gynaecology & Obstetrics
[{'content': 'A 28 weeks pregnant multigravida with preeclampsia presented with fulminant signs. Urgent C-section was planned. Best method for the diagnosis of lung maturity is: \nSelect and explain. \nA. L/S ratio in amniotic fluid, B. Phosphtidyl glycerol estimation in amniotic fluid, C. Bilirubin in amniotic fluid, D. Amniotic fluid creatinine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Phosphatidylglycerol (PG) is a minor constituent of surfactant. It begins to increase appreciably in amniotic fluid several weeks after the rise in lecithin. Its presence is more indicative of fetal lung maturity because PG enhances the spread of phospholipids on the alveoli. Ref: Mehta S.H., Sokol R.J. (2007). Chapter 13. Methods of Assessment for Pregnancy at Risk. In A.H. DeCherney, L. Nathan (Eds), CURRENT Diagnosis & Treatment Obstetrics & Gynecology, 10e.', 'role': 'assistant'}]