This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Which of the following is NOT a MAO inhibitor? 
Select and explain. 
A. Tranylcypromine, B. Isocarboxazide, C. Phenelzine, D. Maprotiline
D: Maprotiline
Answer: D: Maprotiline 
Explanation: Maprotiline is not an MAO inhibitor whereas the rest three are. Ref: KD Tripathi 8th ed.