A class of animals known as Marsupials is a characteristic feature of

Marsupials are a distinct group of mammals commonly known as pouched mammals, characterized by a short gestation and development of the newborn in a pouch attached to the mother’s nipples [1]. While marsupials occur in the Americas as well, the Australian (Australasian) region — encompassing Australia, New Guinea and nearby islands — is their principal stronghold, hosting the majority of extant marsupial families and well-known species such as kangaroos, wallabies, koalas and bandicoots [2]. For this reason marsupials are regarded as a characteristic feature of Australia’s fauna, making option (2) the correct choice [2].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 12: Animal Diversity of India > L?..3,2, Marsupials > p. 190
2. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > 5. australian region > p. 13