Answer: C. Evaporation exceeds precipitation.
Evaporation is the change from liquid to gas and gradually becomes less as a result of the movement of the gaseous particles to the atmosphere. Precipitation on the other hand means to rain. With this, when evaporation exceeds precipitation, it leads to higher levels of salinity as the water being evaporated goes to the atmosphere thereby increasing the concentration of the salt in the water left on the ground as the salt does not go to the atmosphere with the water. With this, excess water leaves the salt and this makes the water remaining much more saline.