What? Can you explain what you're saying better?
Answer:
C. Age of Mammals
Explanation:
Cenozoic is derived from Greek word meaning NEW LIFE. The Cenozoic Era witnessed the disappearance of Dinosaurs which made Mammals to thrive and giving a new life to mammals. During this early stage as new life is beginning, majority of the animal species are relatively small comprising of the small mammals, birds, reptiles and amphibians.
True, temperature and precipitation affect the overall weather and climate of a place.
Gravity, if it isn't and answer please comment back and tell me