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
Ear infection causes throat infection through - 
Select and explain. 
A. Blood spread, B. Eustachian tube, C. Nasocranial spread, D. Simultaneous infection
B: Eustachian tube
Answer: B: Eustachian tube 
Explanation: None