This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Which of the following statements is true about nitrates ? \nSelect and explain. \nA. Acts by raising cGMP which causes dephosphorylation of MLCK, B. Metabolized by glutathione reductase, C. Used in achalasia cardia, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]