Which of the following statements is correct in the rock-salt structure of an ionic compound?

The coordination number of cation and anion in fluorite ${\mathrm{CaF}}_2$ and anti-fluorite ${\mathrm{Na}}_2\mathrm{O}$ are respectively:

In the closest packing of atoms A (radius = r), the radius of atom B that can be fitted into tetrahedral void is:

KF crystallizes in the $\mathrm{NaCl}$ type structure. If the radius of ${\mathrm{K}}^{+}$ions $132\mathrm{pm}$ and that of $\mathrm{F}$ ion is $135\mathrm{pm}$, what is the closest $\mathrm{K}-\mathrm{K}$ distance?