Assertion (A): Eighty per cent of marine pollution comes from land.

Reason (R): Mining for materials such as copper and gold is a major source of contamination in the ocean.

1. Both A and R are true and R is one of the reasons for A.
2. Both A and R are true but R does not explain A.
3. A is true but R is false.
4. A is false but R is true.

Both A and R are true but R does not explain A.

Explanation — Mining for materials such as copper and gold is indeed a major source of contamination in the ocean. However, many other activities such as spreading of harmful substances like oil, plastic, industrial and agricultural waste and chemical particles into the ocean contribute to the mentioned eighty per cent of marine pollution from land.