Answer:
B. Foreign Aid
Step-by-step explanation:
Foreign aid is the most important component of the United States if we're talking about foreign policy.
For example:
The American Country had $49 billion in all for 2014 for foreign aid, Centroamerica countries like Honduras has received a lot of money for education and tourism.
USAID has helped in marginal areas given better education, and they have created two beautiful and ecologic parks for tourism.