A rigid is plated at 12,000 kg MAM but is running empty at 7,200 kg. Which licence do you need?

1. C1 is enough, because today's mass is under 7,500 kg
2. Rijbewijs C, because category follows MAM on the plate, not today's actual mass
3. B is enough when empty
4. No goods-vehicle licence is needed for an empty truck