Answer: C. To encourage them to support military actions.
In this passage of Kennedy's inaugural address, the president discusses what he believes are the responsibilities of this generation of Americans. He argues that this is a critical time, when there are many threats to freedom from many different fronts. He thinks that people should realize that hard work can help the country protect freedom all over the world. This implies military action in countries that are not free or democratic. Therefore, Kennedy's ultimate goal is to encourage citizens to support military actions in other nations.