What is one responsibility that is unique to United States citizens?

Serving on a jury is a responsibility that is unique to United States citizens because it is a civic duty that signifies the citizen's active participation in the judicial system. In the U.S., juries are composed of citizens who are called upon to evaluate evidence and make decisions in legal cases. This duty is a critical aspect of the democratic process, ensuring that peers from the community are involved in the administration of justice.

While paying taxes, voting in elections, and following the law are important responsibilities, they are not exclusive to U.S. citizens. For instance, residents or non-citizens might also be subject to laws and may pay taxes under certain circumstances. Voting, while generally reserved for citizens, can occur under different regulations in other countries and is not unique to the U.S. The same applies to following the law, which is a requirement for all individuals within a jurisdiction, regardless of their citizenship status. Thus, serving on a jury is distinctively tied to citizenship, making it a paramount responsibility of U.S. citizens.