Which contains the largest number of ions?

A.     1 mol of ${\text{A}}{{\text{l}}_{\text{2}}}{({\text{S}}{{\text{O}}_{\text{4}}})_{\text{3}}}$

B.     1 mol of ${\text{M}}{{\text{g}}_{\text{3}}}{{\text{(P}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{2}}}$

C.     2 mol of ${{\text{K}}_{\text{3}}}{\text{P}}{{\text{O}}_{\text{4}}}$

D.     3 mol of ${\text{NaN}}{{\text{O}}_{\text{3}}}$

C