What factor allowed the Incas to use their military efficiently?

they developed an extensive system of paved stone roads

they created a unique record-keeping system for military campaigns

they adopted Spanish military technology and used them against their enemies

they used rivers to transport their troops

Question

What factor allowed the Incas to use their military efficiently?

 they developed an extensive system of paved stone roads

 they created a unique record-keeping system for military campaigns

 they adopted Spanish military technology and used them against their enemies

 they used rivers to transport their troops

kymber · Answer

This sounds like a history question

anonymous · Answer

It is

kymber · Answer

And this is the writing group.

anonymous · Answer

Yeah...This should be in the History section for more help. :P