The condition that will increase the evaporation of water is (a) Increase in temperature of water.
Explanation: As water temperature increases, the molecules gain more kinetic energy, allowing them to move faster and more readily escape from the liquid surface to become vapor, which is the process of evaporation.
Why the other options are incorrect:
(b) Decrease in temperature of water:
Lower temperatures slow down the movement of water molecules, making it less likely for them to overcome the forces holding them in the liquid state and evaporate.
(c) Less exposed surface area of water:
Evaporation occurs at the surface of water. A smaller surface area means fewer water molecules have the opportunity to evaporate.
(d) Adding common salt to water:
Salt dissolved in water can hinder the movement of water molecules at the surface, slowing down the evaporation process.