What is the legal limit for blood alcohol concentration (BAC) when driving a private motor vehicle in Nigeria?

1. 0.02% (20 mg per 100 ml of blood)
2. 0.05% (50 mg per 100 ml of blood)
3. 0.08% (80 mg per 100 ml of blood)
4. 0.10% (100 mg per 100 ml of blood)