The creation of irrigation would have had the biggest effect on which of these? a) agriculture b) buildings c) metallurgy d) politics

A) Agriculture

^^ Not really sure so don't take my word for it.

I would say A. Agriculture.

Irrigation is "the supply of water to land or crops to help growth, typically by means of channels. "

first industrial revolution - the first wave of the industrial revolution lasted from the late 1700s to the mid-1800s. it industrialized the manufacture of textiles and began the move of production from homes to factories. steam power and the cotton gin played an important role in this period.

an economic reason that the south needed a reconstruction plan is that plantations, factories, and other businesses were destroyed during the war.