This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Primary Angle-Closure Glaucoma, Subject name: Ophthalmology
Which muscarinic agonist is used in the treatment of angle closure glaucoma? 
Select and explain. 
A. Pilocarpine, B. Neostigmine, C. Brimonidine, D. Dipiveffine
A: Pilocarpine
Answer: A: Pilocarpine 
Explanation: Ans. is 'a' i.e., Pilocarpine Angle closure glaucomao Treatment of choice for acute congestive glaucoma - Laser iridotomy (1st choice), Peripheral iridectency (2nd choice)o Drug of choice for acute congestive glaucoma - Pilocarpineo Initially IOP is controlled (first drug used) - Systemic mannitol or acetazolamideOpen angle glaucomao Treatment of choiceo Drug of choiceo Surgery of choiceTopical antiglaucoma drugsb - blocker (Timolol, betaxolol, levobunalol)Argon or diode laser trabeculoplasty