Which of the following is incorrect statement

Options

A. Density decreases in case of crystals with Schottky 's defect.
B. `NaCl(s)` is insulator , silicon is semiconductor , silver is conductor , quartz is piezo electric crystal .
C. Frenkel defect is favoured in those ionic compounds in which sizes of cation and anions are almost equal.
D. `FeO_(0.98)` has non stoichiometric metal deficiency defect.

Answer

C