The correct option is D presence of new food
When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive and cause decline or extinction of indigenous species. They prey on native species or outcompete them for food and shelter in the absence of natural predators. Nile perch were introduced to Lake Victoria in the 1950s to boost the fishing industry. Though the introduction of Nile perch resulted in an economic boom, it almost caused cichlids, a native fish, to go extinct. As in the absence of natural predators and presence of new food, i.e. the cichlids, the Nile perch increased in number and led to the extinction of the cichlids by feeding on them.