Answer:
a.cultural diffusion
Explanation:
Cultures are picking up characteristics (inventions in this case) from other cultures, and are being spread.
The technology necessary for navigating such journeys had not yet been invented. Ships had to become better, then they needed maps and charts, compasses, and anything similar.
Territory, the American's actually just purchased Alaska to help Russia out after the Crimean War, however, it gave them new territory in the Pacific region. At the time of the purchase, the public wasn't in support of it. However, later on, the purchase proved to be quite beneficial as Alaska proved to have oil reserves that the US can tap into.
C. is assembly line
A. is vertical integration
B. is horizontal integration