Some organisms are sensitive to different levels of air pollution and are used as pollution - indicators. Suggest which among the following fits into the category

Lichens are widely used as pollution indicators.

Explanation:

• Lichens are highly sensitive to air pollutants, especially sulfur dioxide (SO₂).

• They absorb most of their nutrients directly from the atmosphere. Even slight increases in pollutants can damage or eliminate them.

• Their presence indicates clean air, while their absence signals high levels of air pollution.