During the Cenozoic,animals Grew to Great Sizes and Proportions

Multiple Choice

During the Cenozoic,animals grew to great sizes and proportions.The woolly mammoth and the saber tooth tiger were much larger than animals we see today.Some of the causes for their extinction may be

A) the emergence of man and competition for food.
B) burning of the grasslands,severe climatic change,and man's emergence.
C) dwindling food supplies,extreme climatic variation,and man's emergence.
D) the extensive ice sheets that covered the land surface.