from President John F. Kennedy's Inaugural Address, 1961

"To our sister republics south of our border, we offer a special pledge: to convert our good words into good deeds, in a new alliance for progress; to assist free men and free governments in casting off the chains of poverty. But this peaceful revolution of hope cannot become the prey of hostile powers. Let all our neighbors know that we shall join with them to oppose aggression or subversion anywhere in the Americas.
And let every other power know that this Hemisphere intends to remain the master of its own house."

Which sentence best explains how the bolded portion develops the author's ideas in this paragraph?

It provides a specific example to show the importance of having a strong military presence in countries that oppose the U.S.
It supports the idea that while the country will seek peace and help other countries, it will not be a weak victim to others.
It offers an alternative plan to the peaceful revolution mentioned earlier in the paragraph and shows that the country will use force.
It extends the animal/master metaphor established in the first part of the paragraph to show how powerful the U.S. is.