The correct option is (c) pollution.
Some of the factors that affects the level of water table are temperature, pressure, time of the year(season). Pollution is not the factor affecting the level of water table as pollution can contaminate the water and make it unsuitable for commercial use or industrial use but it does not decreases or increases the level of water table. The factors that affects the level of water table are the internal factors. Example, the water level rises during winter and spring and gradually decreases in summer season. Pumping rates can be thousand gallons per minute for the aquifers and this make a significant change in water levels.