Why Did Athenian Democracy Include Broad Participation by the Citizenry

Why did Athenian democracy include broad participation by the citizenry?

A) Participation ensured that Athens was governed by as wide a representation of its citizenry as possible.
B) Participation ensured Athens was always prepared for war.
C) Participation prepared every citizen for the possibility he or she might need to negotiate for Athens.
D) Participation ensured that Athens would not become a tyranny.
E) Participation encouraged citizens to vote.