Regarding the extinction of dinosaurs and the rise of mammals, which statements are true?
a. Dinosaurs suddenly disappeared from the Earth about 65 million years ago (mya).
b. Some say climatic changes killed the dinosaurs, while others suggest most evolved into birds.
c. The first mammals were viviparous and protected their unborn young inside the mother’s body.
d. Mammals were generally more intelligent than the reptiles that dominated the era.
e. Whales and dolphins are examples of mammals that evolved wholly in water.
