This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
[{'content': 'Tolerance develops by which of the following drug: \nSelect and explain. \nA. Calcium channel blockers, B. ACE inhibitors, C. Nitrates, D. K channel openers', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. NitratesTolerance develops to nitrates when they constantly present in blood. Therefore, it is preferred via sublingual route as it act for short period of time.', 'role': 'assistant'}]