Which of the drivers stopped in violation of the Road Traffic Rules on a road in a built-up area, if it is known that the drivers of the tractor and the truck with a maximum permissible mass exceeding 3.5 tonnes stopped without the need for loading or unloading, and the driver of the bus stopped without the need for boarding or alighting of passengers?

• 1The drivers of the truck, the tractor, and the bus.
• 2The drivers of the truck and the tractor.
• 3The drivers of all vehicles.
• 4No one is committing a violation.