A stable ecosystem is maintained with the interaction of

The correct option is predator-prey.

An ecosystem remains stable when the populations of its various organisms are kept in balance. The interaction between predators (the hunters) and prey (the hunted) is one of the most critical mechanisms for maintaining this ecological balance.
This dynamic interaction prevents any single species from overpopulating or facing unchecked depletion.

For example, if the prey population increases, it provides more food for the predators, leading to an increase in the predator population. Eventually, the growing number of predators consumes more prey, causing the prey population to decline. As the prey population drops, the food supply for predators is reduced, which subsequently decreases the predator population. This cyclical feedback loop keeps both populations in a healthy, stable equilibrium over time.