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': 'A woman complains of coloured halos around lights in the evening, with nausea and vomiting, IOP is normal; Diagnosis is: \nSelect and explain. \nA. Incipient stage glaucoma open angle, B. Prodromal stage, closed angle glaucoma, C. Migraine, D. Raised ICT', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The patient in question presents with symptoms suggestive of glaucoma, but a normal IOP on examination. This is therefore most likely a case of Prodromal stage of Glaucoma. Ref: Concise Textbook Of Ophthalmology By Sharma, Page119 ; Clinical Ophthalmology By Kanski, 3rd Edition, Page 255 and 4th Edition, Page 213 ; Comprehensive Ophthalmology A K Khurana 4th Edition, Page 225', 'role': 'assistant'}]