Final answer:
The Cenozoic era is the present geological era, and we are currently living in it. It is characterized by the dominance of mammals and the development of man.
Step-by-step explanation:
The correct answer is b. Cenozoic. We are currently living in the Cenozoic era, which began about 65 million years ago and is characterized by the dominance of mammals and the development of man. The Cenozoic era is divided into three periods: the Paleogene, Neogene, and Quaternary. The Paleogene period is further divided into the Paleocene, Eocene, and Oligocene epochs.
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