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 20-year-old man complains of difficulty in reading the newspaper with his right eye, three weeks after sustaining a gun shot injury to his left eye. The most likely diagnosis is: 
Select and explain. 
A. Macular edema, B. Sympathetic ophthalmia, C. Optic nerve avulsion, D. Delayed vitreous haemorrhage
B: Sympathetic ophthalmia
Answer: B: Sympathetic ophthalmia 
Explanation: Ans. Sympathetic ophthalmia