Answer:
The correct answer is A. The eon of the geological time scale that means "visible life" is the Phanerozoic.
Step-by-step explanation:
The Phanerozoic Aeon is a division of the geological time scale that extends from 542.0 ± 1.0 million years to the present day. It replaces the Precambrian, which covers the time remaining since the formation of the Earth. Its name derives from the Greek and means "visible life", referring to the size of the organisms that arose at this time. Long before this eon life on Earth already existed, however it is during this period when living organisms already take complex forms, evolve and diversify widely.