Unless a sign imposes a lower limit, what are the Road Traffic Act Article 21 speed limits for Category C vehicles in a built-up area, outside a built-up area, and on a motorway?

1. 50 km/h, 90 km/h, and 140 km/h
2. 50 km/h, 80 km/h, and 90 km/h
3. 50 km/h, 80 km/h, and 100 km/h
4. 40 km/h, 50 km/h, and 90 km/h