The answer I believe is A
A. doves cause doves were trained to go to specific places to give orders and commands. :)
The main way in which the Aztecs used slaves to benefit their economy was for mining purposes. There was not a lot of field work to be done, so most slaves were employed in hard labor.
I believe the answer is: 3. The canals and temples in the city show advanced engineering skills.
The site shows that the Aztec civilization had developed a very advanced irrigation system that utilize different elevation to obtain water for their agricultural field. Their system was later adopted by the spanish empire who invaded their territory.
