Assertion: Lichens contain only one type of organism within them.

Reason: Lichens thrive in polluted areas.

Both the assertion and reason are false.

The correct answer is Option (4) - Both the assertion and reason are false.

Assertion: Lichens contain only one type of organism within them.This statement is incorrect. Lichens are not a single organism but a symbiotic association between two different organisms—a fungus and an alga or cyanobacterium. The fungus provides structural support and absorbs water and nutrients, while the alga or cyanobacterium photosynthesizes to produce food. They exist as a composite organism, displaying characteristics of both partners.

Reason: Lichens thrive in polluted areas.This statement is incorrect. Lichens are recognized as excellent bioindicators of environmental health. They are sensitive to air quality and pollution, particularly sensitive to sulfur dioxide and heavy metals. Instead of thriving, lichens tend to be greatly affected by pollution, often declining or absent in polluted areas due to their sensitivity to environmental changes.