The correct answer to this open question is "Mesozoic."
The continents assumed their current positions during the Mesozoic era.
The Mesozoic Era began approximately 250 million years ago. It is dived in the Triassic period, Jurassic period, and Cretaceous period. During the Cretaceous period of the Mesozoic Era, the continents of planet Earth started to move and accommodate its present positions. The Mesozoic era ended 66 million years ago with the "Great Extinction," where more than 75% of living beings dead.