Scientists find various fossils of a particular prehistoric mammal in successive layers of sedimentary rocks. But, as they moved closer to surface, after a few layers (spanning around 10,000 years) the fossils of that mammal disappeared. The disappearance of the fossils indicates the period when

Options

A. Sediment formation stopped
B. The mammal became extinct
C. The mammal was heavily preyed upon
D. Earth was not undergoing any changes