Among the following, the aqueous solution with highest boiling point is

According to colligative properties of solution, the boiling point is greater for the compound which will give more number of ions in solution. The compounds glucose and urea are non-electrolytes and they don’t produce ions in the solution. Hence, we will get only single molecule for glucose and urea in solution.

For NaCl, two ions $\left({\mathrm{Na}}^{+}{\mathrm{Cl}}^{-}\right); For BaC{l}_2,$ total three ions $\left({\mathrm{Ba}}^{+2},2{\mathrm{Cl}}^{-}\right)$. Therefore, among the given all solutions,  0.1 M  ${\mathrm{BaCl}}_2$ has the highest boiling point.