Which group of animals has a closed circulatory system featuring a single circuit and two heart chambers?

tunicates

amphibians

fish

birds

mammals

Answer;

Fish

Explanation; Fish have a simple circulatory system, which consists of a two-chambered heart, blood, and blood vessels. The circulatory system of fish is a closed circulatory system, in which blood is always contained in a circuit of blood vessels. Fish have a single systemic circuit in which the heart pumps the blood to the gills to be re-oxygenated (gill circulation), after which the blood flows to the rest of the body and back to the heart.