A, it is the current era, and D, it was also known as the age of mammals.
Answer:
A planet is an object that orbits the Sun in an elliptical orbit, has compounded its matter in a spherical shape and has cleared its orbit of other debris. While a dwarf planet also orbits the Sun, has compounded its matter in a spherical shape, but has not cleared its orbit of other debris.
Explanation:
So A .
