Answer: Marsupial
Step-by-step explanation:
The marsupials are the mammals which exhibit a pouch to keep their young ones. These mammals give live birth to the young ones, but they do not exhibit a long gestation period. They have a short gestation period. They give birth to a embryo that climbs from the mother birth canal to the nipples to derive milk. The entire development of the young embryo takes place inside the mother pouch.
On the basis of the above description, marsupial is the correct option.