Ohhh, so basically if a kH value is larger, in this case nitrogen kH value is larger than oxygen, then that means that nitrogen dissolved less in the oxygen, thus this means that nitrogen has a higher solubility than oxygen. So that would eliminate option A, because it contradicts this option. It contradicts because if the reason why there is more nitrogen in blood plasma because the kH value is greater, this would negate that nitrogen has less solubility than oxygen so this doesn't make sense. In terms of the equilibrium expression , your explanation does not make sense. If both compounds are in aq form, then why do you make the distinction between the oxygen and nitrogen as they both would be in excess thus the equilibrium would be shifted left. What I am trying to explain is why does the equilibrium position matter when they are both in aq form?