Concept:Biotic factors are the living components of an ecosystem, such as plants, animals, and microorganisms.
Explanation:A parasite is a living organism that lives on or inside another organism.
A predator is a living organism that hunts and feeds on other organisms.
A grazer is a living organism that feeds on plants or grass.
All three are living things, so they are biotic factors.
Pressure is a physical force, not a living organism.
Therefore, pressure is not a biotic factor but an abiotic factor.
Answer:D. pressure