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
[{'content': 'Kusumlata presents with acute painful red eye and mild dilated veically oval pupil. Most likely diagnosis is: \nSelect and explain. \nA. Acute retrobulber neuritis, B. Acute angle closure glaucoma, C. Acute anterior uveitis, D. Severe keratoconjunctivitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Acute painful red eye and mild dilated veically oval pupil give the diagnosis of acute angle closure glaucoma. Ref: Comprehensive Ophthalmology By AK Khurana, 2nd Edition, Page 232', 'role': 'assistant'}]