Hydrogen reduces solid iron(II,III) oxide according to $\mathrm{Fe}{}_3\mathrm{O}{}_4(\mathrm{s})+4\mathrm{H}{}_2(\mathrm{g})\rightleftharpoons 3\mathrm{Fe}(\mathrm{s})+4\mathrm{H}{}_2\mathrm{O}(\mathrm{g})$, for which $K_p=40$ at the working temperature. At equilibrium the gas phase (only $\mathrm{H}{}_2$ and $\mathrm{H}{}_2\mathrm{O}$) is at a total pressure of 2.0 atm. The partial pressure of $\mathrm{H}{}_2\mathrm{O}$ in atm is

1. A$1.00$
2. B$1.95$
3. C$0.57$
4. D$1.43$