Answer:
Option A
Step-by-step explanation:
The Cenozoic era is considered as the era of new life. It is the third era of the earth's history.
Biologically, the rise of mankind is observed in this period. It is also called "Age of Mammals" because the biggest land creatures were mammals at that time. Many other species were also evolved but mammals were highlighted.
Here, the rabbit is the only mammal in the above options that is why the presence of mammal indicates the Cenozoic era.