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 patient presented with unilateral proptosis, which was compressible and increases on ending forward. No thrill or bruit was present. MRI shows a retro-orbital mass with enhancement. The likely diagnosis is: 
Select and explain. 
A. AV malformations, B. Orbital encephalocoecle, C. Orbital varix, D. Neurofibromatosis
C: Orbital varix
Answer: C: Orbital varix 
Explanation: Ans. Orbital varix