If `10^(-4) dm^(3)` of water is introduced into a `1.0 dm^(3)` flask to `300K` how many moles of water are in the vapour phase when equilibrium is established ? (Given vapour pressure of `H_(2)O` at `300K` is `3170Pa R =8.314 JK^(-1) mol^(-1))` .
A. `5.56xx10^(-3)"mol"`
B. `1.53xx10^(-2)"mol"`
C. `4.46xx10^(-2)"mol"`
D. `1.27xx10^(-3)"mol"`