Question

rabbits introduced into australia over 100 years ago have become a serious pest to farmers. rabbit populations increased so much that they displaced many native species of plant eaters. what is the most logical explanation for their increased numbers?
a there are few effective predators.
b additional rabbit species have been introduced.
c there is an increase in rabbit competitors.
d rabbits have a high death rate.

Explanation:

In an ecosystem, if there are few effective predators, the population of the prey (in this case, rabbits) can grow rapidly. Competitors (option C) would limit growth, a high death rate (option D) would decrease population, and introducing more rabbit species (option B) is not relevant as the problem is about the existing rabbit population.

Answer:

A. There are few effective predators.