Answer: The correct answer is d. All of the above.
Step-by-step explanation:
During the Mesozoic Era, which lasted from about 252 to 66 million years ago, all of the following appeared:
a. Birds
b. Dinosaurs
c. Mammals
Birds are believed to have evolved from a group of small, theropod dinosaurs during the Mesozoic Era. Dinosaurs were the dominant group of land-dwelling vertebrates during this time and included a wide range of species, from small, bird-like dinosaurs to large, fearsome predators like Tyrannosaurus rex. Mammals also appeared during the Mesozoic Era, although they were small and relatively inconspicuous compared to the dinosaurs. These early mammals were mostly small, shrew-like creatures that lived alongside the dinosaurs.