The correct answer is marsupials.
Marsupials are any members of the mammalian class Marsupialia and are endemic to Australasia and the Americas. The main characteristic common to these species is that most of the young are carried in a pouch because they give birth to relatively undeveloped young. Examples of marsupials include kangaroos, wallabies, koalas, possums, opossums, wombats, and Tasmanian devils.