Answer:
3. both of the above
Explanation:
Living things interact with each other. Suppose you have a pond. It is an ecosystem. The fish in the pond interact with each other, and may even interact with other species like frogs or insect by eating them or living peacefully with them. Living things also interact with their environment such as fishes or some organisms might interact with the plants, logs, the available sunlight, all sorts of these factors which make up the environment.
Thus organisms within an ecosystem interact with each other and their environment.
