Which of the following factors contributed most to the expansion of both the Persian and Greek empires.
A. Industrial productivity
B. Religious tolerance
C. Independent city-states
D. Military conquest

Question

Which of the following factors contributed most to the expansion of both the Persian and Greek empires. 
A. Industrial productivity
B. Religious tolerance 
C. Independent city-states
D. Military conquest

anonymous · Answer

D. Assuming that this is referring to the same list of options that was posted before with this question, it was "military organization" since this is what allowed both empires to consolidate power.