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
Longest acting thiazide diuretic is: 
Select and explain. 
A. Chlorthiazide, B. Chlorthalidone, C. Indapamide, D. Metolazone
B: Chlorthalidone
Answer: B: Chlorthalidone 
Explanation: Chlorthiazide : Shortest acting
Chlorthalidone : Longest acting