Answer: Option (a) is the correct answer.
Step-by-step explanation:
Solubility of a gas can be increased by increasing the pressure on a gas. As on increasing the pressure, the molecules come closer to each other and the number of gas molecules will decrease as the molecules are dissolving due to increase in pressure.
On increasing the temperature, the kinetic energy of molecules will increase. Therefore, the gas molecules will move randomly rather and will not be soluble.
Thus, we can conclude that on increasing the pressure we can increase the solubility of a gas.