Abraham and isaac??um just two guesses of mine.
Constantinople was the capital city of the Roman Empire (330–395), .... The city was briefly renamed Augusta Antonina in the early 3rd century AD by the .... an undivided empire (detail from the Obelisk at the Hippodrome of Constantinople).
The industrial revolution! it resulted in farmers leaving rural areas to work in machinery in urbanized cities
The Aztecs demanded that a tribute in goods be paid to them, after they conquered a specific land. As long as the tribute was paid (which ensured their financial position), it was beneficial for them if the conquered people didn't revolt (too much), and if they didn't need to extend funds and infrastructure to govern them- that way they could pay little and maximize their gain. It was practical to reinstall the old rulers in the conquered lands, if they were sure of their loyalty, as it would minimize conflict and need for intervention (such as sending a lot of people into the new land) and maximize their profit.
Both B and D would work for this question but I would choose D