Concept:Water pollution is caused when harmful substances enter water bodies and change their physical, chemical, or biological state.
Explanation:Pesticides used on land are carried by wind and rain into water bodies, contaminating them.
Human activities like factory emissions, vehicle fumes, industrial waste, and sewage also pollute water.
As population grows, more waste and activities (like washing clothes) near water increase pollution.
Therefore, all three factors – pesticides, human activity, and population growth – are reasons for water pollution.
Answer:D. All of the above