Which of the following exhibits the greatest freezing-point lowering?

The freezing point of a solution increases with the number of ions present.

$\begin{array}{l}\mathrm{NaCl}\rightleftharpoons {\mathrm{Na}}^{+}+{\mathrm{Cl}}^{-}\\ {\mathrm{CaCl}}_2\rightleftharpoons {\mathrm{Ca}}^{2+}+2{\mathrm{Cl}}^{-}\\ {\mathrm{CHCOOH}}_3\rightleftharpoons {\mathrm{CH}}_3\mathrm{COO}+{\mathrm{H}}_3^{+}{\mathrm{O}}^{+}\\ {\mathrm{CH}}_3\mathrm{CONNa}\rightleftharpoons {\mathrm{HC}}_3{\mathrm{CO}}_2^{-}+{\mathrm{Na}}^{+}\end{array}$

${\mathrm{CaCl}}_2$ 3 ions dissociate here and are created.