The Ancient Greek Synoikismos or Synoecism Meant

The ancient Greek synoikismos or synoecism meant:

A) borrowing useful inventions from Egypt, Israel, Assyria, and Persia.
B) combining the best of ancient cultures to make a better society.
C) the gradual coming together of a people into a unified political and geographic entity.
D) disbelief in the goodness of the gods.
E) the act of banishing a citizen from a city for a limited period of time.