Answer:
The text structure helps the author convey his central idea in this chapter:
B. By contrasting the outcomes of Spartan and Roman conquests, Machiavelli provides evidence to support his claim that a prince must destroy a free city in order to hold it.
Step-by-step explanation:
Niccolò Machiavelli, born in 1469, was an Italian political philosopher and statesman. The excerpt we are analyzing here belongs to his book "The Prince", published in 1532.
The structure of the passage contrasts the results of different conquests. According to Machiavelli, whenever a country conquers another, it is important to rule it personally or through an oligarchy, or to ruin it. Those are the ways to hold that country, keep it in one's possession. Any other way will lead to losing it.
That is why he mentions the Spartans and the Romans. The Spartans lost the lands they conquered because they gave them too much freedom. The Romans, on the other hand, were able to hold certain countries only because they dismantled them. This contrast serves as evidence to support the ideas above.