The van der Waals constants of a gas are $a=6.49{\mathrm{L}}^2\mathrm{atm}\mathrm{mo}{\mathrm{l}}^{-2}$ and $b=0.0562\mathrm{L}\mathrm{mo}{\mathrm{l}}^{-1}$. If $1\mathrm{mol}$ of this gas at $400\mathrm{K}$ occupies $0.800\mathrm{L}$, the ratio $P_{\text{vdW}}/P_{\text{ideal}}$ is closest to ($R=0.0821\mathrm{L}\mathrm{atm}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$)

1. A0.83
2. B0.93
3. C1.00
4. D1.08