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
A 60 year old male patient operated for cataract 6 months back now complains of floaters and sudden loss of vision. The diagnosis is: 
Select and explain. 
A. Vitreous hemorrhage, B. Retinal detachment, C. Central retinal aery occlusion, D. Cystoid macular edema
B: Retinal detachment
Answer: B: Retinal detachment 
Explanation: Retinal detachment