Answer:
B) Increased US support for the construction of a canal.
Step-by-step explanation:
Based on this map, we can assume that the construction of a canal enjoyed reasonable support in the United States. As we can see in the map, travelling from New York to San Francisco was extremely difficult before the construction of the Panama Canal. This shortened the time it took to travel significantly. It most likely also led to increased trade. Therefore, it is likely people supported the construction of such a project.