Before the Development of Radiometric Dating Techniques Scientists Were Unable

Before the development of radiometric dating techniques scientists were unable to

A) determine the relative order of significant biological events in the fossil record.
B) estimate the absolute age of the abrupt changes in the fossil record.
C) make comparisons between fossil sequences in different parts of the earth.
D) only compare fossil sequences at different levels of sediment.
E) All of the answers are correct.