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: Anatomy
True regarding the development of ear: 
Select and explain. 
A. Eustachian tube opens at the level of interior turbinate, B. Pinna develops from the cleft of Ist arch, C. Growth of the inner- ear completed by 4th month, D. All
D: All
Answer: D: All 
Explanation: A i.e. Eustachian tube opens at the level of inferior turbinate; B i.e. Pinna develops from the cleft of arch; C i.e. Growth of inner ear completed by 4th monthEustachian tube connects tympanic cavity with nasopharynx. It is about 36cm long in adults and runs downwards, forwards & medially at an angle of 45deg with horizontal from bony tympanic end to slit like pharyngeal end. Tympanic end is in the anterior wall of middle ear, just above the level of floor. While nasopharyngeal end is situated in the lateral wall about 1 -1.25 cm behind the posterior end of inferiro turbinateQ