This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'Which of the following is NOT a first line antihypeensive agent? \nSelect and explain. \nA. Enalapril, B. Hydrochlohiazide, C. Amlodipine, D. Atenolol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A/C/D are first-line antihypeensives A-ACE inhibitors and ARBs C-calcium channel blockers D-Diuretics Beta blockers are not 1st line agents due to side effect profile (Ref-. Essentials of medical pharmacology K D TRIPATHI 8th Edition)', 'role': 'assistant'}]