Which of the incorrect statement?

• A. FeO0.98 has non stoichiometric metal deficiency defect.
• B. Density decreases in case of crystals with Schottky’s defect.
• C. NaCl(s) is insulator, silicon is semiconductor, silver is conductor, quartz is piezo electric crystal
• D. Frenkel defect is favoured in those ionic compounds in which sizes of cation and anions are almost equal