When they were first discovered in Australia in 1798, the duck-billed, beaver-tailed platypuses so defied categorization that one scientist assigned them the name Ornithorhynchus paradoxus: "paradoxical bird-snout." The animal, which lays eggs but also nurses ________ young with milk, has since been classified as belonging to the monotremes group.

Which choice completes the text so that it conforms to the conventions of Standard English?