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
Muller's maneuver is - 
Select and explain. 
A. Forceful expiration against closed glottis, B. Forceful inspiration against closed glottis, C. Forceful expiration against open glottis, D. Reverse of Valsalva maneuver
D: Reverse of Valsalva maneuver
Answer: D: Reverse of Valsalva maneuver 
Explanation: None