Which of the following aqueous solutions will exhibit highest boiling point ?

${\mathrm{\Delta T}}_{\mathrm{b}}=\mathrm{i}\times {\mathrm{K}}_{\mathrm{b}}\times \mathrm{m}$

$\mathrm{i}\times \mathrm{m}\text{ of }{\mathrm{Na}}_2{\mathrm{SO}}_4$ is highest, hence its boiling point will also be highest

${\mathrm{Na}}_2{\mathrm{SO}}_4\to \mathrm{i}\times \mathrm{m}=3\times 0.01=0.03$

${\mathrm{KNO}}_3\to \mathrm{i}\times \mathrm{m}=2\times 0.01=0.02$

$\text{ Urea }\to \mathrm{i}\times \mathrm{m}=1\times 0.015=0.015$

$\text{ Glucose }\to \mathrm{i}\times \mathrm{m}=1\times 0.015=0.015$