This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitreous and retina, Subject name: Ophthalmology
[{'content': 'Marcus-Gunn sign is seen in - \nSelect and explain. \nA. Retinitis pigmentosa, B. Retinal detachment, C. Diabetic retinopathy, D. Hypeensive retinopathy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: causes of Marcus Gunn pupil. (In swinging flashlight test, the pupil on the diseasedside dilates on transferring light to it) \x01 Optic neuritis \x01 Optic atrophy \x01 Retinal detachment \x01 Central retinal aery occlusion \x01 Central retinal vein occlusion Ref Comprehensive ophthalmology AK Khurana 4th edition page no 494', 'role': 'assistant'}]