Question

Which of the following is the earliest era?

• A. Coenozoic
• B. Mesozoic
• C. Paleozoic
• D. Pre-cambrian

Answer 1

The correct option is D Pre-cambrian

Geological Time scale is the vast expanse of geological time has been separated into eras, periods, and epochs.

All geologic time before the beginning of the Paleozoic era is known as Precambrian era. This includes about 90% of all geologic time and spans the time from the beginning of the earth, about 4.5 billion years ago, to 544 million years ago. It is the largest span of time in Earth's history. Hence, option D is correct.