The correct answer to this open question is the following.
Although there are no options attach, we can say the following.
The oligarchy of Greece decided to make changes around 630 B.C because the oligarchy realized they had not enough people to fight the poor in Greece.
It was a time in ancient Greece where a small group of powerful people controlled the government of the region. That is what oligarchy means. It was a time before the dawn of Democracy, a concept created by Cleisthenes in Athens.
The Greek oligarchy ruled before democracy, and they were aristocrats, an elite and wealthy class that imposed its will over the poor people.