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 medications is the drug of choice for severe preeclampsia? \nSelect and explain. \nA. Labetalol, B. Metoprolol, C. Alpha-methyldopa, D. Nifedipine', 'role': 'user'}, {'content': "Answer: A \nExplanation: Labetalol is a adrenoreceptor antagonist which is used in the treatment of severe pre-eclampsia. Although Metoprolol, Alpha methyldopa and Nifedipine are used in the treatment of severe pre-eclampsia, both Hydralazine and Labetalol has emerged as the first line drugs to control the hypeension in severe pre-eclamptic patients. Ref: Dewhurst's Textbook of Obstetrics and Gynaecology By Keith Edmonds; 8th edition, Pages 101-09; Dutta textbook of Obstetrics 6th edition, Pages 221-42", 'role': 'assistant'}]