$6.0\mathrm{g}$ of urea (molar mass $60$) and $18\mathrm{g}$ of glucose (molar mass $180\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$) are dissolved to make exactly $1.0\mathrm{L}$ of solution at $27{}^{\circ }\mathrm{C}$. The osmotic pressure is ($R=0.0821\mathrm{L}\mathrm{atm}\mathrm{mo}{\mathrm{l}}^{-1}{\mathrm{K}}^{-1}$)

1. A$4.93\mathrm{atm}$
2. B$2.46\mathrm{atm}$
3. C$9.85\mathrm{atm}$
4. D$14.8\mathrm{atm}$