Which aqueous solution would possess the lowest boiling point?

Note: All the concentrations are given as $\raisebox{1ex}{$\mathrm{w}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{w}$}\right.\%$.

$\left(\mathrm{Na}=23 \mathrm{u}, \mathrm{Cl}=35.5 \mathrm{u}, \mathrm{C}=12 \mathrm{u}, \mathrm{O}=16 \mathrm{u}, \mathrm{H}=1 \mathrm{u}, \mathrm{N}=14 \mathrm{u}\right)$

The elevation in the boiling point of a solution of $13.44 \mathrm{g}$ of ${\mathrm{CuCl}}_2$ in $1 \mathrm{kg}$ of water using the following information will be,

(Molecular weight of ${\mathrm{CuCl}}_2=134.4, {\mathrm{K}}_{\mathrm{b}}=0.52 \mathrm{K} {\mathrm{molal}}^{-1}$)

(Assuming $100\%$ dissociation)

Maximum freezing point for $1 \mathrm{m}$ solution will be of

(assuming equal ionization in each case)