Solubility of a gas in a liquid increases with

Calculate the solubility of a gas in a solvent at $25^{\circ} C$ and $0.8 \ atm$ if Henry's law constant for the solvent is $6.8 \times 10^{-4} \ mol \ dm^{-3} \ atm^{-1}$.

Calculate the solubility of a gas in water at $260 \ mm \ Hg$ and $25^{\circ} C$ if Henry's law constant of the gas is $0.159 \ mol \ dm^{-3} \ atm^{-1}$ at $25^{\circ} C$.

Assertion : When a salt such as $NaCl$ dissolves,the $Na^{+}$ and $Cl^{-}$ ions leaving the crystal lattice acquire far greater freedom.
Reason : In thermodynamic terms,the formation of solution occurs with a favourable change in free energy,i.e.,$\Delta H$ has a high positive value and $T\Delta S$ a low negative value.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Helium is used to dilute oxygen in diving apparatus.
Reason $R$: Helium has high solubility in $O_2$.
In the light of the above statements,choose the correct answer from the options given below:

Carbonated water is an example of a solution of