Final answer:
The correct order of the divisions in the geologic time scale is eons, eras, and periods. These categories are used to frame Earth's history and major biological and geological changes.
Step-by-step explanation:
The relative order of the divisions of the geologic time scale from largest to smallest is eons, eras, and periods. This means the correct answer to the question is option 1: Eons, Eras, Periods. Each division reflects major changes in Earth's geology, climate, and life forms. For example, the Earth’s history is first divided into large extents of time called eons. The Hadean, Archean, Proterozoic, and Phanerozoic are the eons, with the first three collectively sometimes referred to as the Precambrian. These eons are further subdivided into eras, and within these, periods exist. Periods can be divided into epochs and finally ages. Understanding the geologic time scale is critical for grasping the Earth's history and the evolution of life.For instance, the Phanerozoic eon is divided into three eras: the Paleozoic, Mesozoic, and Cenozoic. Each era is further broken down into periods, like the Jurassic period of the Mesozoic era. Events such as mass extinctions or significant evolutionary milestones often define these divisions. The geologic timescale is a tool that helps us understand the Earth's history in a structured and easily referenceable manner.