Final answer:
Option C is answer. Precambrian time is larger than other geologic eras due to extensive geological activities, the formation of Earth's fundamental elements, and the lengthy evolution of early life.
Step-by-step explanation:
The Precambrian time is so much larger than the other eras on the geologic time scale primarily because of the extensive geological activities and the formation of fundamental elements for life that took place during this period. Spanning from around 4.6 billion years ago to about 541 million years ago, the Precambrian includes the formation of Earth, the solidification of its molten surface, the appearance and development of the oceans and atmosphere, as well as the emergence of the first living organisms. Given the dramatic geologic and climatic changes that happened in this vast span of time, it encompasses the majority of Earth's history, providing a substantial amount of time for first life forms such as stromatolites to appear and evolve.
The Late Precambrian, specifically from about 2 billion to half a billion years ago, was a period of significant evolutionary changes. Life forms that couldn't adapt died out, making way for organisms with new adaptations such as sexual reproduction, the specialization of cells, and multicellularity. The Precambrian mass extinction at the end of this eon led to the Cambrian explosion where a diversity of life forms rapidly evolved.