No overtaking permitted for commercial vehicles with an all up weight of more than 4,000 kg but may overtake a Motorcycle

What is the meaning of the following traffic sign?

1. Correct answer: No overtaking permitted for commercial vehicles with an all up weight of more than 4,000 kg but may overtake a Motorcycle
2. No overtaking or bypassing of motor vehicles for any vehicle with an all up weight of more than eight tons.
3. A commercial vehicle with an all up weight of at least 14 tons is permitted to overtake or bypass a motor vehicle with more than 2 wheels.
4. No overtaking for vehicles with an all up weight of more than 12 tons.