Answer: b. It was a failed biological control mechanism for cane beetles.
Explanation:
An invasive species is the one which is introduced either intentionally or accidentally into a new habitat is responsible for causing harm to the native species by competing it for resources.
A cane toad was an invasive species native to Florida and was introduce to Australia to get rid of cane beetles damaging the sugarcane crops. These toads were capable to control the beetles to some extent but they became competitive with the native species. They were poisonous and were responsible for killing the other organisms of the native land.
