The vapour pressure of pure water at $25^{\circ }\mathrm{C}$ is $23.8\mathrm{mmHg}$. A solution is prepared by dissolving $90\mathrm{g}$ of glucose (molar mass $180\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$) in $180\mathrm{g}$ of water (molar mass $18\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$). Taking glucose as non-volatile, the vapour pressure of the solution in mmHg is closest to

1. A24.93
2. B22.61
3. C22.67
4. D1.13