Answer:
C. . how old they are
Step-by-step explanation:
Geologist are people that deal with the internal structure of the earth.
They study Rocks, and it's deposit accumulated millions of years back.
They can also give account of what happened in the past and the types of organisms that existed in the past.
Fossils are traces of event, remains of dead animals and decomposed object.
So geologist can give account of how many years a particular fossil has lived in that particular environment.
