Answer:
A. a tragic characters reversal of fortune
Explanation:
An amendment to the Constitution must be approved by 3/4 of the states (A). That's why it's so difficult for an amendment to be ratified.
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.
The Industrial Revolution transformed economies that had been based on agriculture and handicrafts into economies based on large-scale industry, mechanized manufacturing, and the factory system. New machines, new power sources, and new ways of organizing work made existing industries more productive and efficient.