Biology

The correct answer is: B.Algae.

Here's why:

Algae: Algae are living organisms, so they are biotic factors in the ecosystem. Biotic factors are the living components of an ecosystem, such as plants, animals, and microorganisms.

Now, let’s go over the other options:

A.Air: Air is an abiotic factor because it is a non-living component of the ecosystem. It provides gases like oxygen and carbon dioxide that are essential for life, but it is not living....