This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glaucoma, Subject name: Ophthalmology
[{'content': 'Drug of choice for primary open angle glaucoma: \nSelect and explain. \nA. Beta blockers, B. Prostaglandin analogues, C. Alpha agonists, D. Cholinergics', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Prostaglandin analogues are now the drug of choice for open angle glaucoma and normal tension glaucoma.', 'role': 'assistant'}]