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
Which of the following is NOT a first line antihypeensive agent? 
Select and explain. 
A. Enalapril, B. Hydrochlohiazide, C. Amlodipine, D. Atenolol
D: Atenolol
Answer: D: Atenolol 
Explanation: 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)