Answer:
They set up a system of spies.
Explanation:
The two empires mentioned above were very influential and successful in creating a spy system, where they sent spies to enemy nations, or nations, that would be conquered. In this way, spies gained valuable information about the weaknesses of cities, as well as governmental and leadership weaknesses that could be exploited to bring about a governmental downfall and successful control over the Maurya or Aśoka empires. This espionage system was one of the main factors that allowed the Maurya to conquer northern India.
