The absence of a thumb is a characteristic feature of ........

Which characteristic is found exclusively in mammals?

Choose the correct option for the following statements:
$(i)$ Animals that maintain a constant body temperature are called $cold-blooded$ / $warm-blooded$ animals.
$(ii)$ Mammals are $viviparous$ / $oviparous$ animals.

Pick the mammal with a true placenta.

Which of the following characteristics is associated with the group of mammals?

Mammals that possess a marsupium (pouch) are called .....