According to Austrian and EU vehicle construction regulations (turning circle / BO-Kraft circle), a bus must be capable of turning within an annular track with what dimensions?

1. An outer radius of max 10.0 metres and inner radius of min 4.0 metres
2. An outer radius of max 15.0 metres and inner radius of min 7.0 metres
3. An outer radius of max 20.0 metres and inner radius of min 10.0 metres
4. An outer radius of max 12.50 metres and an inner radius of min 5.30 metres under KFG § 4