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.

WhyA red truck on the sign means trucks heavier than 4,000 kg may not overtake motor vehicles. They may overtake a motorcycle.