MICROANATOMY

Detailed explanation-1: -So, the correct answer is ‘The way in which its young one’s develop’.

Detailed explanation-2: -Placental mammals all bear live young, which are nourished before birth in the mother’s uterus through a specialized embryonic organ attached to the uterus wall, the placenta. The placenta is derived from the same membranes that surround the embryos in the amniote eggs of reptiles, birds, and monotreme.

Detailed explanation-3: -A marsupial is a mammal that raises its newborn offspring inside an external pouch at the front or underside of their bodies. In contrast, a placental is a mammal that completes embryo development inside the mother, nourished by an organ called the placenta.

Detailed explanation-4: -Mammals that carry their young in an abdominal pouch during their early development are called marsupials. Soon after the marsupial ovum, or egg, is fertilized, the young are born in a premature state and crawl into the mother’s pouch. There, nursing on milk from their mother’s nipples, they complete their development.