$\text{ In the unit cell of }\mathrm{KCl}\text{ ( }\mathrm{NaCl}\text{ type), }{\mathrm{Cl}}^{-}\text{ions constitute }\mathrm{ccp}\text{ and }{\mathrm{K}}^{+}\text{ions fall into the octahedral holes. These holes are: }$

$\text{ one at the centre and }6\text{ at the centres of the faces }$

$\text{ one at the centre and }12\text{ at the centres of the edges }$

$8\text{ at the centres of }8\text{ small cubes forming the unit cell }$

$\text{ none of these }$