Correct option is B
Eutrophication is primarily caused by the
excessive discharge of nutrients, particularly nitrogen and phosphorus, into water bodies. These nutrients promote the overgrowth of algae and aquatic plants, which can lead to decreased oxygen levels and harm aquatic life.
Excessive discharge of suspended solids: Can contribute to water quality issues but is not the primary cause of eutrophication.
Excessive discharge of nutrients: Correct, as it leads to nutrient enrichment and eutrophication.
Excessive discharge of chlorides: While it affects water quality, it is not the primary cause of eutrophication.
Discharge of toxic substances: Can harm aquatic life but does not directly cause eutrophication.
Therefore, the correct answer is (b) Excessive discharge of nutrients.
