Question

multiple - choice question
this early technology allowed factories to expand across the nation.....
coal fired engines
electricity
gas powered machines
steam engines

Explanation:

Steam engines were crucial in the Industrial Revolution. They provided a reliable source of power that was not dependent on water wheels (which were location - specific). This allowed factories to be set up in more locations across a nation. Coal - fired engines (steam engines often used coal as fuel, but the more general and key term here is steam engines). Electricity came later in the industrial development timeline. Gas - powered machines also became prominent after the initial spread of factories enabled by steam.

Answer:

steam engines