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
Fundus examination of a patient presenting with loss of vision revealed a Cherry red spot on the macula. What is he most likely suffering from? 
Select and explain. 
A. Retinitis pigmentosa, B. Retinoblastoma, C. CRAO, D. CRVO
C: CRAO
Answer: C: CRAO 
Explanation: Cherry red spot on the retina is seen in central retinal aery occlusion. Other retinal signs in this condition includes retinal oedema and segmentation of blood column in the retinal vein (cattle tracking sign). Patients often presents with sudden painless loss of vision. Reference: Comprehensive Ophthalmology By A K Khurana, 4th Edition, Page 255.