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: ENT
A patient with sinus infection develops chemosis ,B/L proptosis and fever, the diagnosis goes in favour of- 
Select and explain. 
A. Lateral sinus thrombosis, B. Frontal lobe abscess, C. Cavernous sinus thrombosis, D. Meningtitis
C: Cavernous sinus thrombosis
Answer: C: Cavernous sinus thrombosis 
Explanation: Angular vein which begins from medial angle of eye, continues as the facial vein. The facial vein communicates with the cavernous sinus through the deep facial vein and pterygoid plexus of veins.
B/L proptosis, fever and chemosis point towards cavernous sinus thrombosis.