Which animal group have mammary glands for the production of milk ?

Aves Amphibia Mammalia Reptilia

Mammalia

The correct answer is Option (3) – Mammalia Mammals are warm-blooded animals with four-chambered hearts. They have mammary glands for the production of milk to nourish their young. Their skin has hairs as well as sweat and oil glands. Most mammals familiar to us produce live young ones.