This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: ENT
The Eustachian tube opens into nasopharynx approximately 1 cm behind the: 
Select and explain. 
A. Tonsil, B. Posterior end of superior turbinate, C. Posterior end of middle turbinate, D. Posterior end of inferior turbinate
D: Posterior end of inferior turbinate
Answer: D: Posterior end of inferior turbinate 
Explanation: (d) Posterior end of inferior turbinate(Ref. Scott Brown, Vol 3; 738)Eustachian tube opens in the lateral wall of nasopharynx about 1.25cm behind the posterior end of inferior turbinate.Around 1cm behind the posterior end of middle turbinate is the sphenopalatine foramen. This is the most common site for origin of angiofibroma.There is no opening behind the superior turbinate.Tonsils are present in the oropharynx.