Answer:
domesticated animals were used to haul food over long distances
Trevor noah says at the bottom of the article on bold text
I think letter C is the closest. <span />
The California Gold Rush of 1849-1855 radically transformed California, the United States and the world. ... The significant increase in population and infrastructure allowed California to qualify for statehood in 1850, only a few years after it was ceded by Mexico, and facilitated U.S. expansion to the American West.
