This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
[{'content': 'Hiatus semilunaris is present in? \nSelect and explain. \nA. Superior meatus, B. Middle meatus, C. Inferior meatus, D. Spheno-ethmoidal recess', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Middle meatus: Uncinate process is a hook-like structure running in from anterosuperior to the posteroinferior direction in the middle meatus. It&;s postero superior border is sharp and runs parallel to the anterior border of bulla ethmoidalis. This gap between the two is called hiatus semilunaris .it is two-dimensional space of 1-2 mm width. (Ref: Diseases of Ear, Nose and Throat and head and neck surgery, Dhingra 7th edition, Pg no. 150)', 'role': 'assistant'}]