If the number of herbivores decreases, what effect can it have on carnivores?

Correct answer: Food shortage may occur

The direct answer is A: a food shortage may occur for carnivores. In a food chain, plants are eaten by herbivores, and herbivores may be eaten by carnivores. Therefore, if herbivores decrease, carnivores have fewer usual prey animals. Step by step: fewer herbivores means fewer prey; fewer prey means less available food; competition among carnivores may increase, and some may become weak or move elsewhere. Option A is correct because it describes this possible result. Option B is wrong because carnivores cannot become plants; plants make their own food, while carnivores obtain food by eating other organisms. Option C is wrong because every animal still needs food, water and suitable habitat. Option D is wrong because fewer prey normally makes survival and reproduction harder, so carnivore numbers will not always increase. The word “may” is important: the effect is possible, not guaranteed in every situation. Memory cue: when prey decreases, the predator’s food supply usually decreases too.