Answer: overpopulation of predators.
Explanation:
Overpopulation of predators is the correct option. Predators are the organisms which kill other organism so as to obtain them as food. The organism being killed is called as the prey.
If the population of the predators increase this will lead to the extinction of many species of prey. As it is evident that every organism in the ecosystem has a typical role to play. Therefore, it can be said that role of prey will not be performed and this may lead to disturbance in the ecological balance.