The correct answer is option A. "Excess salt deposited in the soil when irrigation water evaporates".
Explanation:
Nonpoint source pollution is a type of contamination which results from the combination of more than one source of pollution, which contrasts with point source pollution that results from an unique source. An example of nonpoint source pollution that might occur on a farm is excess salt deposited in the soil when irrigation water evaporates. In this example, the excess of salt in the soil occurs from more than one source: irrigation, water evaporation, and the excess of salt in water.
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