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: Ophthalmology
Treatment of primary open angle glaucoma: 
Select and explain. 
A. Timolol maleate, B. Atropine, C. Acetazolamide, D. Prostaglandin analogue
A: Timolol maleate
Answer: A: Timolol maleate 
Explanation: Ans. Timolol maleate