This vehicle is immobilized due to a breakdown. Must its driver warn other road users of its presence?
A)No; only drivers of trucks and buses are required to do so.
B)Outside built-up areas it is mandatory, being optional on urban roads.
C)Yes, and hazard warning triangles shall be used.Correct
# Explanation
When a vehicle is immobilized due to a breakdown, the driver **must mandatorily warn** other road users to prevent accidents. The correct way to do so is by using **hazard warning triangles**, which must be placed at a reasonable distance from the vehicle (minimum 50 meters on fast roads). This obligation applies to all types of roads, both urban and interurban.