Concept: Gas solubility depends on the solvent, the solute, temperature, and pressure.Explanation:The nature of both the solute and the solvent determines whether a gas will dissolve easily.Temperature affects gas solubility because higher temperatures generally reduce the amount of gas that can dissolve.Pressure significantly affects gas solubility, as increased pressure forces more gas into solution.Therefore, all four factors listed are important.Answer: A. I, II, III and IV