Why is the geologic record important to scientists

The geologic record is the history of Earth as recorded in the rocks that make up its crust. Rocks have been forming and wearing away since Earth first started to form, creating sediment that accumulates in layers of rock called strata. The way these strata are arranged and what fossils are in them give scientists clues about what Earth was like billions of years ago.

B. a circuit. i think

I'm pretty sure the answer is c