A key difference between the Greek city-states and the city-states of Mesopotamia, or the city-states of Mesoamerica, was that
a. Most of the Greek city-states developed direct democracies
b. Many of the Greek city-states were under the collective rule of local nobles
c. Many of the Greek city-states allowed some freedoms for women
d. Most of the Greek city-states were ruled by cruel leaders called tyrants