A right creates an opportunity.
A right gives a person a protected opportunity to act. A legal duty, by contrast, requires particular conduct. The question tests this distinction through electoral participation. The matching answer is therefore “a right”.
People may encourage others to learn about an election and vote. Such an appeal is not a legal order. A personal belief that one ought to use one’s vote does not change the legal classification either.

The other three answers
The incorrect words describe an obligation, compulsion or a personal judgement.
a duty.
Germany has no legal duty to vote. Calling voting a “civic duty” morally does not automatically mean legally enforceable participation.
compulsory.
Compulsion contradicts the freedom tested here. An eligible voter must not be forced to choose a particular party or candidate.
a burden.
Whether someone experiences an activity as a burden is a personal judgement. The legal classification of participation is a right.
Voluntary participation and regulated procedure coexist.
The right belongs to those eligible for the particular election. It does not mean everyone may vote in every election regardless of age or other conditions. Eligibility is distinct from deciding whether actually to participate.
A person who chooses to vote follows the prescribed procedure. Freedom to participate does not remove rules about ballots, polling places or postal voting. Those rules organise the exercise of the right.
Article 38 · Basic Law ↗Being allowed to vote is a right; being required to vote would be a duty.
The German rule is that there is no legal obligation to vote.
Three words for this question
- das Rechtright
- A legally protected entitlement or opportunity.
- die Pflichtduty / obligation
- Required conduct, here distinct from a moral appeal.
- Gebrauch machen vonto exercise / make use of
- To actually use an available opportunity.
