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': 'Which of the following drug is not used in the treatment of preterm labour? \nSelect and explain. \nA. Ritodrine, B. MgSO4, C. Salbutamol, D. Chlorpromazine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ritodrine, salbutamol and magnesium sulphate are tocolytic drugs used to terminate preterm labour and delivery. Other tocolytic drugs are isoxsuprine, indomethacin, calcium channel blockers, glyceryl trinitrate, atosiban and glyceryl trinitrate. Reference: Textbook of Obstetrics By D C Dutta, 6e page 508.', 'role': 'assistant'}]