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
Not a test for Eustachian tube patency ? 
Select and explain. 
A. Tympanometry, B. Toynbee, C. Valsalva, D. Frenzel maneuver
A: Tympanometry
Answer: A: Tympanometry 
Explanation: Ans. is 'a' i.e., Tympanometry Tests for Eustachian tubepatency Valsalva test Methylene blue test Sonotubometry Politzer test Toynbee test Frenzel maneuver Catheterization Inflation - Deflation test