Out of the following, select those that would help to reduce water pollution.

(i) Use of sewers for removal of urban waste 

(ii) Use of unleaded petrol in cars

(iii) Spraying of pesticides on plants

(iv) We should not excrete in open

We can reduce water pollution by not excreting the waste in open. Human waste can contain harmful pathogens and pollutants that can contaminate water sources and harm aquatic life and human health. Proper sanitation facilities, such as toilets and sewage systems, are necessary to prevent water pollution from human waste.

Sewers are a safe and efficient way to remove urban waste, including wastewater, from homes and businesses. When properly treated, this wastewater can be released back into the environment without causing harm to aquatic life or human health.

The use of unleaded petrol in cars helps to decrease air pollution and spraying of pesticides on plants can cause water pollution.