Which of the following is a mandatory instruction sign type in airfield driving?

The correct response highlights a specific type of sign that serves a critical function in maintaining safety on the airfield. Mandatory instruction signs are designed to provide essential commands that must be followed by pilots, vehicle operators, and ground personnel. These signs generally convey instructions such as "Stop," "No Entry," or any other directive that is imperative for safe operations within the airfield environment.

Understanding the role of mandatory instruction signs is key for maintaining safety and organization on the airfield. They often use red backgrounds with white lettering to ensure they are easily recognizable and distinguishable from other types of signs. Their presence helps prevent accidents and ensures that all personnel adhere to necessary safety protocols, particularly in high-traffic areas.

While other sign types, such as runway identification signs, taxiway direction signs, and information signs, also play important roles in airfield operations, they do not carry the same level of urgency for compliance as mandatory instruction signs. For instance, runway identification and taxiway direction signs primarily aid in navigation, whereas information signs provide general information but do not require action.