The correct answer is: B. epochs
An epoch is a geological period of time that is shorter than an era but longer than a period. Epochs are typically defined by major events in the Earth’s history, such as the formation of new continents or the extinction of major groups of organisms.
The Phanerozoic eon, for example, is divided into the Paleozoic, Mesozoic, and Cenozoic eras. The Paleozoic era is further divided into the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods. The Mesozoic era is further divided into the Triassic, Jurassic, and Cretaceous periods. The Cenozoic era is further divided into the Paleogene, Neogene, and Quaternary periods.
The Quaternary period is the most recent epoch, and it is still ongoing. It is divided into the Pleistocene and Holocene epochs. The Pleistocene epoch is characterized by repeated glaciations, while the Holocene epoch is characterized by the current interglacial period.
Aeons are the longest units of geological time, and they are typically defined by major events in the evolution of the universe. The Phanerozoic eon, for example, is part of the Proterozoic aeon, which is part of the Archean aeon, which is part of the Hadean aeon.
Stages are the shortest units of geological time, and they are typically defined by minor events in the Earth’s history. For example, the Cambrian period is divided into the Lower Cambrian, Middle Cambrian, and Upper Cambrian stages.
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