This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
A patient admitted in casualty after RTA- shows bruising behind the mastoid- This sign is known as. 
Select and explain. 
A. Prehn sign, B. Battle sign, C. Catel Sign, D. Dietel's sign
B: Battle sign
Answer: B: Battle sign 
Explanation: Ans. (b) Battle sign* Battle sign is due to Fracture of base of skull* Middle cranial fossa fracture is associated with Battle sign