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': 'Calcium channel blockers are used in all except \nSelect and explain. \nA. Angina, B. Arrythymia, C. Congestive hea failure, D. Hypeension', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Calcium channel blockers prevent calciumfrom entering cells of the hea and blood vessel walls, resulting in lower blood pressure. Calcium channel blockers, also called calcium antagonists, relax and widen blood vessels by affecting the muscle cells in the aerial walls Refer kDT 6/e p 502,551', 'role': 'assistant'}]