Final answer:
The correct answer to the categories of Mammalia is d) all of the above. This includes monotremes like the platypus, marsupials such as kangaroos, and a wide range of placental mammals, including humans.
Step-by-step explanation:
The three categories of Mammalia are: a) Prototheria, Metatheria, and Eutheria; b) Monotremes, Marsupials, and Placentals; c) offspring finish gestation in an egg, offspring finish gestation in an external pouch, and offspring finish gestation in an internal organ. Since each option describes the grouping of mammals based on reproductive strategies with different terminologies, the answer is d) all of the above. Monotremes, such as the platypus and echidnas, lay eggs and are known as prototherians. Marsupials, which include animals like kangaroos and koalas, give birth to underdeveloped embryos that complete their development in an external pouch; these belong to the Metatheria. The majority of mammals are placentals or Eutherians, which develop their young internally with the aid of a placenta. Examples of placental mammals are humans, dogs, and cats.