Final answer:
The Proterozoic era is associated with the time period from 2.5 to 0.6 billion years ago. It saw the evolution of eukaryotic cells and precedes the Phanerozoic eon starting with the Cambrian explosion.
Step-by-step explanation:
The Proterozoic era is associated with 2.5 to 0.6 Ga (billion years ago), which is option (c) in the question provided. During this era, the Earth saw significant geological, climatic changes and important developments in life, including the evolution of eukaryotic cells and the advent of multicellular organisms. The Proterozoic eon eventually gave way to the Phanerozoic eon which began with the Paleozoic era, marked by the Cambrian explosion of diverse and complex life forms.
The Proterozoic era is further divided into the Paleoproterozoic Mesoproterozoic and Neoproterozoic eras, with the Neoproterozoic being the last and hosting periods such as the Ediacaran Period, which preceded the Cambrian Period of the Paleozoic Era. The Neoproterozoic Era included three periods with the Vendian Period being one of them extending from approximately 635 million to 541 million years ago, leading up to the Cambrian explosion.