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
Prussak's space is situated in: 
Select and explain. 
A. Epitympanum, B. Mesotympanum, C. Hypotympanum, D. Ear canal
A: Epitympanum
Answer: A: Epitympanum 
Explanation: (a) Epitympanum(Ref. Cummings, 6th ed., 1983)The space of the epitympanum, lying in between the Shrapnell's membrane or pars flaccida and the neck of malleus is known as "PRUSSAK'S SPACE".When the retraction pocket on Pars flaccida grows medially, it goes into this Prussak's space making this the most common site of primary cholesteatoma.