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
Kusum lata presents with acute painful red eye and mild dilated vertically oval pupil. Most likely diagnosis is – 
Select and explain. 
A. Acute retrobulbar neuritis, B. Acute angle closure glaucoma, C. Acute anterior uveitis, D. Severe kerato–conjunctivitis
B: Acute angle closure glaucoma
Answer: B: Acute angle closure glaucoma 
Explanation: Mild dilated (semidilated), vertically oval pupil is characteristic of acute congestive glaucoma.