The correct statement$(s)$ regarding defects in solids is(are):
$A$. Frenkel defect is usually favoured by a very small difference in the sizes of cation and anion.
$B$. Frenkel defect is a dislocation defect.
$C$. Trapping of an electron in the lattice leads to the formation of $F$-center.
$D$. Schottky defects have no effect on the physical properties of solids.

• A
  $B, C$
• B
  $A, B, C$
• C
  $B, C, D$
• D
  $A, D$