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
Which of the following statements is true about nitrates ? 
Select and explain. 
A. Acts by raising cGMP which causes dephosphorylation of MLCK, B. Metabolized by glutathione reductase, C. Used in achalasia cardia, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None