This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
Toynbee test is used to the function of - 
Select and explain. 
A. Eustachian tube, B. Tympanic membrane, C. Middle ear, D. Semicircular canal
A: Eustachian tube
Answer: A: Eustachian tube 
Explanation: Ans. is 'a' i.e., Eustachian tube Tests for Eustachian tube patency* Valsalva test* Methylene blue test* Sonotubometry* Politzer test* Toynbee test* Frenzel maneuver* Catheterization* Inflation - Deflation test