Correct option (B) ZnS
Explanation:
In ZnS, S2– (sulphide ions) are present at fcc position giving four sulphide ions per unit cell. To comply with 1 : 1 stoichiometry, four Zn2+ ions must be present in four alternate tetrahedral voids out of eight tetrahedral voids present.
In NaCl, Na+ ions are present in octahedral voids while in Na2O, Na+ ions are present in all its tetrahedral voids giving the desired 2 :1 stoichiometry. In CaF2 , Ca2+ ions occupies fcc positions and all the tetrahedral voids are occupied by fluoride ions.
