SOLUTION

The example of a cautionary sign (warning sign) from the options provided is Pedestrian crossing.

• Cautionary Sign: A pedestrian crossing sign is designed to alert drivers and pedestrians about the presence of a crosswalk where pedestrians may be crossing the road. It serves as a warning to drivers to slow down and be prepared to stop for pedestrians.

Analysis of Other Options:

• Stop: This is a regulatory sign that instructs drivers to come to a complete stop and is not classified as a cautionary sign.
• Overtaking prohibited: This is also a regulatory sign that prohibits overtaking in certain areas, rather than warning about potential hazards.
• Petrol pump: This is an informational sign indicating the location of a petrol station, not a warning sign.