Correct Answer : Point-source pollution
Explanation : In point-source pollution, the pollutants reach the water body in points concentrated in space. Usually, the discharge of domestic and industrial wastewater generates point-source pollution.
Correct Answer : Option (B) : Eutrophication
Explanation : Eutrophication is the growth of huge amounts of algae and other aquatic plants leading to the deterioration of water quality. The untreated wastewater is rich in organic matter which demands oxygen.
Correct Answer : Option (C) : 20°C
Correct Answer : Option (D) : All of the above