A scientist found the fossilized remains of a modern badger species in a new layer of sedimentary rock. The fossil was dated to the Holocene geologic epoch. If the scientist wanted to find an ancestor of this species from the Pleistocene geologic epoch, where should she look?
A. in a layer of rock below the badger fossil, since lower layers are usually older
B. in a layer of rock known to be from the Eocene geologic epoch that is at another location
C. in a layer of rock above the badger fossil, since younger layers are usually higher
D. in the same layer of rock in which the badger fossil was found, since related organisms are usually together