Which class includes salamanders, frogs, and toads?

The correct choice is based on the classification of animals within the scientific taxonomy. The class Amphibia is specifically designed to include animals known as amphibians, which comprise salamanders, frogs, and toads.

Amphibians are characterized by their life cycle typically involving both aquatic and terrestrial stages, starting with eggs laid in water that hatch into larvae (like tadpoles) and eventually metamorphose into adults capable of living on land. This class is distinct from Aves (birds), Chondrichthyes (sharks and rays), and Mammalia (mammals), which represent other groups with unique defining features and evolutionary traits.

Therefore, recognizing that salamanders, frogs, and toads all fall under the category of amphibians solidifies why the class Amphibia is the correct answer to this question.