Hiatus semilunaris is present in -: (A) Superior meatus, (B) Middle meatus, (C) Inferior meatus, (D) sphenoethmoidal recess
Answer is B. Important structures of middle meatus are :-


Hiatus semilunaris, 
Ethmoidal infundibulum,
Anterior & posterior fontanelle,
Uncinate process,
Bulla ethmoidalis.