Answer: C. Salt
Irrigation is an agriculture practice of providing the agriculture field with water. It helps in the growth of the agricultural crops, removes the compaction of the soil, prevents the freezing of the soil, and suppresses the growth of weeds.
Irrigation can cause pollution to the soil if the water contains excessive amounts of salts. The plants readily absorbed the moisture from the soil leaving behind the salts in the soil which remains as pollutant and deteriorate the quality of soil and affects the plant growth.
