Final answer:
One responsibility that is only for United States citizens is to serve on a jury.
Step-by-step explanation:
One responsibility that is only for United States citizens is to *serve on a jury*. When a person is called to serve on a jury, they become part of a group of citizens who help make decisions in legal cases. Jury duty is an important civic duty and is required of U.S. citizens to ensure a fair legal system.
Learn more about Responsibilities of United States citizens