Ground water will not be depleted due to
(b) thermal power plants
(c) loss of forest, and decreased rainfall
(d) cropping of high water demanding crops
Afforestation means plantation of trees. Groundwater will not be depleted due to afforestation.
Thermal power plants pollute the groundwater.
Loss of forest and decreased rainfall also pollutes the groundwater.
Most of the groundwater is polluted due to the use of excess water for cropping of high water demanding crops.
Hence option (a) is correct.