The Romans constructed aqueducts throughout their Republic and later Empire, to bring water from outside sources into cities and towns. ... Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone, brick, or concrete; the steeper the gradient, the faster the flow.
Irrigation made it possible to grow rice in very dry climates. ... Irrigation ditches were used to mark the boundaries between crops. Irrigation allowed for the movement of water to fields, even without rain
The best answer is b since everyone had to abide by the same ten commandments, showing that no one was more important (or exempt from law) than another
The large size of the market for European products. The triangular Atlantic slave trade is believed to have been the most convenient and profitable trade route. This is because Ships leaving Europe were only required to carry trade goods on their way to Africa. On arrival to Africa exchange of the goods for slaves took place. To Europeans the trade was always to their favor since cheap goods were of more value to poor African states who complied effectively in the trade.
There were fewer transportation innovations because the rivers were plenty good transportation for farmers and their plantation. I hope I could help :D