Which best explains why the rulers of early civilizations expected people to pay taxes for projects like building canals and city walls?

These projects would benefit the society as a whole so citizens should contribute to them.

Explanation:

Rulers needed to build canals and city walls when there was a great need for such buildings. Because the canals and walls were built to provide protection and improvements for the population, the government believed it was right for the population to contribute taxes. According to the rulers these taxes would return to the population in the form of improvements in the city, similar to what we currently do when we pay our taxes.