What is the correct definition of a 'Specialized tool-equipped vehicle'?

What is the correct definition of a 'Specialized tool-equipped vehicle'?

1. A motor vehicle with a maximum total weight exceeding 3.5 tons.
2. A vehicle equipped with large machinery that can carry additional passengers or goods outside the cabin.
3. A special vehicle equipped with additional machinery, without carrying passengers or cargo outside the cabin.

Correct answer

A special vehicle equipped with additional machinery, without carrying passengers or cargo outside the cabin.

This is the correct answer for the Cambodian driving theory test. Questions are drawn from the official Ministry of Public Works and Transport sign library and road rules.