Frenkel defect is a stoichiometric point defect which occurs in the lattice arrangement of crystalline solids. Frenkel defect is shown by ionic solids where a smaller ion in the lattice, usually a cation, is dislocated and it occupies another site. The site where the ion leaves creates the vacancy defect and the new site of placement is the interstitial defect. This defect is thus known as dislocation defect. The correct answer is (i).