If a scientist wanted to determine if a forest environment had been polluted, which of the following groups of organisms typically would be the BEST indicator for the presence of pollutants?

fish
birds
mammals
amphibians
insects

Option (4)

Explanation:

Amphibians are those organisms that can dwell in both land and water. They have been present on earth since a long time. These amphibians includes frogs, crocodiles, tortoise and many more. These amphibian species have the ability to exchange various types of gases through their body skin. They can sense the environmental pollution, and have low environmental tolerances. They are good indicators for the presence of various toxic gases or pollutants in an forested environment.

Thus, the correct answer is option (4).

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