Angelica saw an example of the geologic time scale in her book while studying the history of the Earth. She is interested in learning more about the geologic time scale, including its purpose. What is the purpose of the geologic time scale?
A. to organize the eras and periods of major events of fossils
B. to organize the kinds of plants and animals that lived during those times on Earth
C. to organize the kinds of rocks in order for people to study the life forms and classify fossils
D. to organize Earth's history in a record of geologic events and show the evolution of life forms