AP World History

Answer - C - The widespread usage of the steam engine played the largest role in the beginning phase of the Industrial Revolution.

Key Takeaway: A steam engine performs mechanical work using steam as its working fluid. The idea of using boiling water to produce motion has a history of nearly 2,000 years. Early devices were not practical, but more advanced designs have become a major source of mechanical power. These designs enabled the Industrial Revolution, beginning with applications for removing mine water with vacuum engines.