Consider Two Containers with the Same Volume and Temperature

Consider two containers with the same volume and temperature.Container One holds "dry" air--a mixture of nitrogen and oxygen.Container Two holds "moist" air.The "moist" air has the same ratio of nitrogen to oxygen molecules,but also contains water vapor.According to the ideal gas law,if the pressures are equal,the weight of the gas in Container One will be

A) lighter than the gas inside the second container.
B) equal to the weight of the gas in the second container.
C) heavier than the gas inside the second container.
D) all the above are incorrect because the pressures cannot be equal.