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
A PATIENT WITH DIABETES AND COPD DEVELOPED POST OPERATIVE URINARY RETENTION .WHICH OF THE FOLLOWING IS USED FOR SO TERM TREATMENT TO RELIVE SYMPTOMS ? 
Select and explain. 
A. BETHANECOL, B. METHANICOL, C. TERAZOSIN, D. TAMSULOSIN
A: BETHANECOL
Answer: A: BETHANECOL 
Explanation: BETHANECOL : ITS A M3 RECEPPTOR ANTAGONIST ITS USES ARE : FOR CONSTIPATION., PARALYTIC ILEUS, POST OPERATIVE URINARY RETENTION . REF : KD TRIPATHI 8TH ED