Which Geologic Eon Denotes the First 800 Million Years of Earth

While the Precambrian represents 88% of Earth's history, it is not divided into periods or epochs like the Phanerozoic because there ________. A)are few remaining Precambrian rocks to correlate or divide due to active tectonics B)are no Precambrian sedimentary rocks to use for internal divisions C)were no multi-cellular organisms nor hard-bodied fauna to leave much of a fossil record D)are few resources in Precambrian rocks and few geologists take an interest in them