Which of the following describes a situation that can occur when very few animals of a species are left and there are less available mates for breeding. A: Succession

B: Predation

C: Catastrophe

D: Rarity

The correct answer is D.

A is specific to plant communities and involves the growing and replacing of previous, less advanced forms of things like forests and shrubs. C refers to any natural disaster and really isn't too influenced by a lack of organisms. B would decrease if anything due to a lack of organisms to eat. D, being the only correct answer, refers to a loss and ultimate extinction.