Answer:
C- rock layers.
Step-by-step explanation:
Stratigraphy is a branch of geology that deals with the study of rock layers (strata) and their sequence, composition, and correlation. It involves the analysis of the physical and chemical properties of rocks, as well as the fossils contained within them, to reconstruct the geologic history of an area. This can include understanding the timing of events such as volcanic eruptions, the deposition of sedimentary layers, and the evolution of life on Earth. By studying the layers of rock, geologists can develop a timeline of Earth's history, including major events such as mass extinctions, the formation of mountains, and the changing climate.