If the Avogadro's number is $1\times 10^{23}$ mol$^{-1}$ then the mass of one atom of oxygen would be

Question

$\begin{array}{1 1}(a)\;\large\frac{16}{6.02}\normalsize a.m.u& (b)\;16\times 10^{-23}a.m.u \\(c)\;16a.m.u&(d)\;16\times 6.02a.m.u\end{array}$