The roman empire reached its greatest?

Question:

The roman empire reached its greatest?

extent in which of the following centries? 2nd, 3rd, 4th, or 5th

Thanks!!!!

Best Answer - Chosen by Asker: While Tanseman is arguably correct in terms of when the Roman empire reached its cultural apex, the greatest extent of the Roman empire was achieved under Trajan following the occupation of Mesopotamia and Armenia. That was in the 2nd century CE. The cultural and societal apex may also have been under the "four good emperors": Nerva, Trajan, Hadrian and Marcus Aurelius. This has been traditionally agreed upon since Edward Gibbon's publication of The Decline and Fall of the Roman Empire in 1776.