Mammals are homothermic and viviparous. This meant that they

Question

1) give birth and have gills
2)have blubber and can lay eggs
3)are warm blooded and give live birth
4)are cold blooded and breathe air

Answer 1

The correct answer is:

3. are warm blooded and give live birth

Mammals are homothermic (or endothermic), which means they maintain a constant body temperature (warm-blooded), and they are viviparous, which means they give birth to live young rather than laying eggs (with some exceptions, like monotremes, which are egg-laying mammals).