Answer:
The answer is d) Permian
Step-by-step explanation:
The Diplocaulus was an animal similar to the salamander that existed during the Permian Period.
Diplocaulus belongs to the group of lepospondyls. Not to be confused with dinosaurs, since this animal lived long before these, this ancient amphibian disappeared when the dinosaurs began to inhabit the earth. This animal inhabited the earth during the Paleozoic Era, in the subdivision called as Permian.