Sodium metal crystallizes in a body centered cubic lattice with a unit cell edge of $44.29 \dot{A}$ the radius of sodium atom is approximately :

Question

$\begin{array}{1 1} 0.93\;\dot{A} \\ 1.86\;\dot{A} \\ 3.22\; \dot{A} \\ 5.72\; \dot{A} \end{array}$