Which of the following is an indicator of industrial pollution?

Lichens

 The correct answer is Option (1)- Lichens

Lichens are sensitive to air pollution, especially sulfur dioxide (SO₂) and other acidic compounds emitted from industrial activities such as burning of fossil fuels and industrial processes. These pollutants can damage the cells of lichens, affecting their growth and survival.

Because lichens absorb water and nutrients directly from the air through their thallus (the main body of the lichen), they can accumulate pollutants present in the atmosphere. As a result, the presence, abundance, and health of lichens in an area can reflect the level of air pollution and the quality of the environment.