What is the statutory passing standard for the official Swiss Category C supplementary theory test (Zusatztheorieprüfung C)?

1. 60 questions, maximum 15 errors allowed
2. 40 questions, maximum 4 errors allowed (minimum 36 correct answers out of 40, 90% pass mark) in 60 minutes
3. 100 questions, 50% passing grade
4. Zero errors permitted on 20 questions