Which of the following is not considered a physical factor of habitat?

In the context of habitat factors, physical factors refer to the non-living elements that can influence the environment and the organisms that inhabit it. Soil, moisture, and temperature are all considered physical factors because they are tangible components of the environment that affect habitat conditions and help determine the types of organisms that can live in that habitat. For instance, soil type can affect nutrient availability for plants, moisture levels can influence water availability for both flora and fauna, and temperature can impact species distribution and metabolic processes.

Predators, on the other hand, are biotic factors because they are living organisms that interact with other living organisms in the ecosystem. They affect population dynamics and community structure through their roles in food webs and predatory-prey relationships. Thus, while predators can significantly influence habitat dynamics, they do not fall under the category of physical factors, making this the correct choice.