The correct answer is A.
Jury duty service is mandatory in the United States.
A person summoned for jury duty must attend and failing to do so is illegal and may be punished.
A jury is panel (group) of people who have to deliver a verdict in a case submitted to them. The panel has to decide whether the accused person is guilty or not.
Employees on jury duty are freed from work on they jury duty days because it is a civil obligation required by the law.
Voting in elections, joining a political party or staying informed of current events are not mandatory duties.