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: Forensic Medicine
All are Atropine substitutes except 
Select and explain. 
A. Procyclidine, B. Propantheline, C. Tiotropium, D. Drotaverin
D: Drotaverin
Answer: D: Drotaverin 
Explanation: Drotaverine (INN, also known as drotaverin) is an antispasmodic drug, used to enhance cervical dilation during childbih. It is structurally related to papaverine, is a selective inhibitor of phosphodiesterase 4, and has no anticholinergic effects. Ref - medscape.com