Consider the following: 1. Butterflies 2. Fish 3. Frogs How many of the above have poisonous species among them?

All three

Poisonous species occur among all three groups. Some butterflies, such as monarchs, accumulate toxic compounds from their larval host plants and become unpalatable to predators. Several fish species, including pufferfish, contain potent toxins. Poison dart frogs and certain other frogs possess toxic skin secretions. Hence, all three groups include poisonous species. Options A and B are incorrect because they underestimate the number of groups containing poisonous species. Option D is incorrect because poisonous species are well documented in each group.