One mole crystal of a metal halide of the type MX with molecular weight 119g having face centred cubic structure with unit cell length `6.58Å` was recrystallized. The density of the recrystallized crystal was found to be `2.44 g cm^(-3)`. The type of defect introduced during the recrystallization is:

Options

A. additional `M^(+)` and `X(-)` ions at interstitial sites
B. Schottky defect
C. F-center
D. Frenkel defect