The correct answer is A.
The rise of dinosaurs did not occur during the Cenozoic era. The time of Mesozoic era is when the rise of dinosaurs discovered. The Cenozoic era is termed as the current geological era. It is the coverage period to present from 66 million years ago.
It is also referred to as the age of mammals reason being large mammals that dominate it. Cenozoic is divided into three periods which include Quarternary, Neogene, and Paleogene. Cenozoic had seven epochs which include Holocene, Pleistocene, Pliocene, Miocene, Oligocene, Eocene, and Paleocene.
Quarternary has recognized by the international commission on stratigraphy. Some other periods which were divided from Cenozoic include Mesozoic and Paleozoic.