** answer asap and you dont need to tell me why just give me the correct

which kind of life form first appeared during the tertiary period?

a.
angiosperms, or flowering plants

b.
large, meat-eating dinosaurs

c.
small, rodent-like mammals

d.
cattle-like mammals that ate grass

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel