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': 'Glyceryl trinitrate route of administration \nSelect and explain. \nA. Oral, B. Submucosal, C. Rectal, D. Sublingual', 'role': 'user'}, {'content': 'Answer: D \nExplanation: GTN is usually given by SL route .kept under the tongue and can be spit it out when sufficient pain relief is obtained.SL-1st pass metabolism can be bypassed. Ref: KD Tripathi 8th ed.', 'role': 'assistant'}]