Which of the following expressions is correct in the case of a $CsCl$ unit cell (edge length,$a$)?

Polonium (atomic mass = $209$) crystallises in a simple cubic structure with a density of $9.32 \ g \ cm^{-3}$. Its lattice parameter (in $pm$) is closest to:

An atomic substance $A$ of molar mass $12 \ g \ mol^{-1}$ has a cubic crystal structure with an edge length of $300 \ pm$. The number of atoms present in one unit cell of $A$ is $.....$ (Nearest integer). Given the density of $A$ is $3.0 \ g \ cm^{-3}$ and $N_{A} = 6.02 \times 10^{23} \ mol^{-1}$.

If a metal crystallises in a face-centred cubic $(FCC)$ structure with a metallic radius of $25 \ pm$, the number of unit cells in $1.0 \ cm^3$ of the lattice is:

$A$ substance has a density of $2 \ g \ cm^{-3}$. It crystallizes in the $fcc$ crystal with an edge length of $600 \ pm$. The molar mass of the substance (in $g \ mol^{-1}$) is
$(N_{A} = 6 \times 10^{23} \ mol^{-1})$

Sodium crystallizes in $bcc$ structure with radius $1.86 \times 10^{-8} \text{ cm}$. What is the edge length of unit cell of sodium?