<em>D. city-states developed mostly independent of each other</em>
The mountainous geography of Greece functioned as natural borders between different settlements. The early Greeks settled in the habitable land between the mountains, which later led to large city-states developing in those areas between the mountains. The mountains would act as borders between the various city-states of Greece.
In 1787, the Framers wanted to create a new government that would be strong enough to meet the nation's needs, but would also preserve the state powers.