Which statement is correct about air leaks, tractor protection, and ABS faults?

1. Drive because the protection valve repairs leaks
2. Air leaks after coupling must be repaired; the tractor protection valve is an emergency safeguard, and an ABS fault means anti-lock protection may be unavailable even if service brakes work.
3. Ignore it if the tractor starts normally
4. Use the trailer hand valve as the main solution