20. What is a biotic factor in a grassland ecosystem? 1. the soil that provides the microorganisms with a home II. worms, fungi, and bacteria that also live in the soil III. grass and other plants that the goat eats IV. hawks, owls and other animals that hunt snakes A. I, II and III B. II, III and IV C. I, II, and IV D. I, II, III and IV