This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Which of the following drugs exhibits narrow therapeutic window phenomenon? 
Select and explain. 
A. Captopril, B. Furosemide, C. Diazepam, D. Imipramine
D: Imipramine
Answer: D: Imipramine 
Explanation: Imipramine exhibit therapeutic window phenomenon. also seen with drugs like phenytoin. lithium.theophylline. so the administrationis to be monitored using therapeutic drug monitoring. Ref: KDT 6/e pg. 46.