When does a vehicle carrying oversize freight require escort?

1. When the vehicle carries hazardous materials.
2. Correct answer: When the width of its freight is more than 3.40 meters.
3. When the vehicle was authorized to carry a heavy load.
4. When the width of its oversize freight is more than 3 meters and its length is more than by 20 meters.

WhyAn escort is needed if the freight is wider than 3.40 m. Heavy freight or dangerous materials alone do not require an escort. The option with a 20 m height is plainly absurd.