Total number of atoms present in $1.0cm^3$ of solid urea (density 0.3g/$cm^3$) at $25^{\large\circ}$ are

Question

$\begin{array}{1 1}(a)\;3.01\times 10^{21}&(b)\;2.41\times 10^{22}\\(c)\;3.01\times 10^{22}&(d)\;2.41\times 10^{23}\end{array}$