An ordinary truck towing a heavy trailer (trailer GLW over 3,500 kg) has a gross combination weight of 14,000 kg. What is the lowest required full licence class, excluding special tractor exceptions?

The ordinary-combination range is 12,001 to 25,000 kg GCW. A rigid vehicle with a light trailer can fall under different provisions; this question specifies a heavy trailer. A higher full licence may also allow the vehicle, but the question asks for the lowest class.