Geological Time Scale

Step 1: Understanding Geological Time Scale.
The geological time scale divides Earth's history into various time units, with "Era" being a major division of time. The Permian is an Era within the Paleozoic Era, not an eon, epoch, or period.
Step 2: Analyzing the options.
(A) Eon: Incorrect — Eons are the largest time division, far larger than eras.
(B) Era: Correct — The Permian is an era within the geological time scale.
(C) Epoch: Incorrect — An epoch is a smaller division than an era.
(D) Period: Incorrect — A period is smaller than an era and typically refers to subdivisions within an era.
Step 3: Conclusion.
The correct answer is (B) Era, as the Permian is an era in the geological time scale.