Respuesta :
It would be the second option about 540 million years ago.
Answer:
Option C, About 540 million years ago
Explanation:
The Phanerozoic Eon started from the end of Precambrian period and consists of three eras namely Paleozoic Era , the Mesozoic Era , and the Cenozoic Era. It also consists of 12 geologic period. The Phanerozoic Eon is still continuing till today since it started some 540 -570 million years ago. It is this period which marks the evolution of complex lifeforms such as invertebrates ,some 500 million years ago.
Thus, option C is the appropriate answer.
