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
The most common cause of cerebrospinal otorrhoea is- 
Select and explain. 
A. Rupture of tympanic membrance, B. Fracture of petrous ridge, C. Fracture of mastoid air cells, D. Fracture of parietal bone
B: Fracture of petrous ridge
Answer: B: Fracture of petrous ridge 
Explanation: None