This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Pharmacology
Which is not an osmotic laxative? 
Select and explain. 
A. Sorbitol, B. Magnesium Hydroxide, C. Polyethylene glycol, D. Bisacodyl
D: Bisacodyl
Answer: D: Bisacodyl 
Explanation: Laxatives Bulk forming Dietary fibre Osmotic Sorbitol Lactulose Polyethylene glycol Mg(OH)2 MgSO4 Stimulant Senna Cascara Bisacodyl