The question asks why the applicant is rejected.
Service work may require particular knowledge and skills. Skin colour says nothing about them. If it alone determines the outcome, a person is treated worse because of a protected characteristic instead of being assessed on suitability.
Protection against discrimination does not begin only after hiring. Section 6 expressly includes job applications. A privately run restaurant is therefore not free to use racist selection criteria.

The other three answers
The other reasons can be relevant, but do not permit arbitrary rejection.
his German skills are too low.
Sufficient language skills may be needed for particular tasks. The requirement must fit the work; excessive or pretextual language demands can themselves discriminate.
he has too high salary expectations.
Different salary expectations may prevent agreement. That is not in itself racial discrimination, but must not disguise a decision actually based on race.
he has no experience in the profession.
Work experience can be an objective selection criterion where relevant to the particular role and applied fairly. Skin colour does not establish experience.
Even neutral wording needs a lawful basis.
Section 3 also covers indirect discrimination: a seemingly neutral rule may particularly disadvantage protected groups. It then requires the objective justification specified by law. The exam does not claim every language or experience requirement is automatically permissible.
Unlawful rejection can give rise to claims. However, section 15 subsection 6 does not automatically create a right to be hired. Evidence, deadlines and possible claims require separate assessment in a real case.
Section 7 · Non-discrimination · General Equal Treatment Act ↗Assess skills; do not use skin colour as a reason for exclusion.
The decisive word is “because”: what reason actually caused the rejection?
Three words for this question
- die Bewerbungjob application
- Seeking a particular job.
- die Eignungsuitability
- Skills and qualifications matching the particular work.
- mittelbare Benachteiligungindirect discrimination
- Particular disadvantage caused by seemingly neutral rules without sufficient justification.
