Which action is considered a mandatory responsibility of us citizenship?

holding political office
serving in the army
serving on a jury
joining a political party

serving on a jury

Explanation:

For the American people, participation in a jury is the duty of every citizen. This duty is constitutionally enshrined as the bulwark of citizens' freedom, since for Americans the exercise of democracy by the participation of the people in public life occurs not only by practicing the right to vote, but also by the performance of the right to integrate Jury court.