Why is all of geologic time before the Cambrian Period sometimes collectively lumped together called the "Precambrian"?

A-We have very few fossils from the time
B-Nothing lived during that time
C-The time period was very short
D-Everything from that time was destroyed by volcanos.​

Which best describes the scientific method? a. a path of clearly defined steps that must be followed in a particular order b. a possible answer to a scientific question based on knowledge or research c. the recipe for how to conduct an experiment that must be followed precisely d. the process of hypothesis and testing through which scientific inquiry occurs