Answer:
c. colonial expansion
Explanation:
Around 1600, Europeans exploited 49 percent of the globe but only 32 percent of the world's land. By the end of the eighteenth century, their knowledge had doubled: 83% of the globe and 60% of the land. This colonial exploitation made the Europeans known to various peoples with different cultures and appearances, this gave them a racial consciousness that they did not have before colonial expansion.
There are 50 states in the US
The assembly line reversed the process of automobile manufacture, but <span>cars were individually crafted by teams of skilled workmen.</span>