Privacy protects independent choice.
Someone who fears that employers, neighbours or authorities can monitor their individual vote may come under pressure. Ballot secrecy therefore protects the choice when the vote is cast. It is one of the constitutional electoral principles.
Eligibility is checked at the polling station, but this should not create a link between a person and the party they mark. Identity checks and ballot secrecy serve different purposes: only eligible people should vote, and their particular choice should remain concealed.

The other three answers
The correct answer names an electoral principle. The other words do not.
special.
“Special” is a vague description. The constitutional principle sought is secrecy.
profession-related.
Bundestag elections are not divided by occupation. A profession does not determine how a vote is counted or whether the choice is protected.
gender-dependent.
Voting rights do not depend on gender. This option substitutes an impermissible distinction for a democratic electoral principle.
A secret vote and public scrutiny are compatible.
The general procedure and determination of the result should be open to public scrutiny. The individual choice is secret. Being able to observe a count does not mean being entitled to watch a particular person mark their ballot.
Permitted help for people unable to perform all necessary actions follows specific rules. An assistant must also keep the choice confidential and must not replace it with their own.
Article 38 · Basic Law ↗The choice stays private; the process stays verifiable.
If the question asks for one suitable word, choose “secret”.
Three words for this question
- geheimsecret
- Here: the individual voting choice is not visible to others.
- die Wahlkabinevoting booth
- A screened place for marking a ballot without observation.
- die Stimmabgabecasting a vote
- The act through which an eligible person casts their choice.
