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
Edema over the mastoid is seen in - 
Select and explain. 
A. Bell's Palsy, B. Lateral sinus thrombophlebitis, C. CSOM, D. ASOM
B: Lateral sinus thrombophlebitis
Answer: B: Lateral sinus thrombophlebitis 
Explanation: Ans. is'b'i.e., Lateral sinus thrombophlebitis (Ref: Dhingra sth/e p. 95) Edema over posterior post of mastoid (Griesinger's sign) is seen in lateral sinus thrombosis (signal sinus thrombosis).