Question

What made the transition from one-at-a-time manufacturing to mass production possible?

discovery of coal
building of factories
child labor laws
new technology

Answer 1

Answer: Let me help you out the answer is:

New Technology

Explanation: the answer is right there when you read the first paragraph of the lesson let me show you:

CALVERT ACADEMY- The Industrial Revolution is marked by a change in production from making things one-at-a-time by hand to making hundreds of items at a time by machines. This shift was made possible by the development of new technology.

there is my evidence to back up my answer hope this helped I know I'm really late...

Answer 2

The answer is the discovery of coal. Coal is used to power the machinery to produce products in a massive number. Machines during the Industrial Revolution thrive on coal energy to work.  Coal was not only used in factories, but they were also used to power transportation, like trains.