Answer:
1. B. The United States must reach all the way to Pacific Ocean.
2. D. Spain
3. B. U.S threatened war with Spain.
Explanation:
1. Manifest destiny refers to the belief that United States must expand, and reach other territories, all the way to the Pacific Ocean and even beyond. This belief is what birthed the idea of United States annexing and purchasing places like New Mexico, Texas, Hawaii etc.
Hence, the correct answer is The United States must reach all the way to Pacific Ocean.
2. The United States acquired Florida from Spain, through negotiations which involves the United States' Secretary of States in the person of John Quincy Adams in 1819, under the Onis - Adam Treaty, in which United States agreed to assume liability for $5 million to Spain, due to damage done by American citizens who rebelled against Spain.
Hence, the answer is Spain
3. Before the acquisition of Florida from Spain by the United States, there were series of negotiations and the incident of Andrew Jackson, a US General, who seized the Spanish Fort in Pensacola and St. Marks. Thus, during the negotiation that seal the deal, John Adams used the military actions of Andrew Jackson to influence the Spanish team to take the decision, citing that, Spain should either control the inhabitants of Florida or cede it to the United States, which is more of threat of war.
Hence, it is considered that, Florida was acquired because U.S threatened war with Spain.