What is irrigation? O Irrigation is the system of bringing water to areas where crops are grown.
O Irrigation is the main source of political power in the Middle East.
O Irrigation is the system whereby countries with water lose their resources to countries without water.
o Irrigation is the system of spreading agriculture through a region.

O Irrigation is the system of bringing water to areas where crops are grown.

Explanation:

The definition of irrigation is the supply of water to land or crops to help growth, typically by means of channels.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.