Question

which type of fossils are used to identify specific time periods?
o trace fossils
o index fossils
o body fossils
o all fossils

Explanation:

Index fossils are distinctive and existed for a short geological time. They are used to identify specific time periods. Body fossils are remains of the organism itself. Trace fossils are evidence of the organism's activity. Not all fossils can be used for this purpose.

Answer:

index fossils