The correct chronological order of the time periods is the following:
Christian era: Is the period where everything begins according to the bible. The era begins with the birth of Christ. (Year 1).
Height of the Roman empire: The Roman empire is the unity of the Mediterranean sea and it is dated around 200AD.
Fall of the Roman empire: This event is dated that happened in 417 CE and it was when the empire fell to enforce its rules and the territory was divided.
Medieval period: This period takes place between the fall of the Roman empire and the renaissance period. (Around the 15th century).
I believe it would be D as the word oppose or opposition means to protest something's occurrence. The sentence is saying that people may protest or disagree with a later start time.
