Final answer:
C. War Production Board
During World War II, the War Production Board was the agency responsible for converting civilian industry to war production and overseeing resource allocation to ensure efficient military supply.
Step-by-step explanation:
The government agency that took over the majority of different industries during World War II was the War Production Board (WPB).
The WPB was responsible for converting and overseeing civilian industry to war production. They had substantial control over what was produced, where it was produced, and how resources were allocated. This federal agency utilized economic planning to manage aspects of the American economy to increase military production while avoiding major hardships on the home front.
Moreover, the government-led efforts allowed for collaboration between private enterprise and unprecedented government intervention, exemplified by offering tax incentives, loans, and profitable partnerships to businesses for wartime production.