(i) Temperature
(ii) Nature of solute
(iii) Pressure
(iv) Nature of solvent
Correct Answer: (iii) Pressure
Explanation: Changes in pressure do not affect the solubility of solids and the liquids that we ignore because the pressure of solids and liquids is almost negligible or very small compared to gases to make them dissolve by increasing the pressure in liquids as easy as liquid gases.