5.85g of NaCl is dissolved in 1L of pure water.The number of ions in 1ml of this solution is

Question

$\begin{array}{1 1}(a)\;6.02\times 10^{20}& (b)\; 6.02\times 10^{19}\\(c)\;1.2\times 10^{20}& (d)\;1.2\times 10^{22}\end{array}$