How many additional resources were called to the scene?

The correct answer indicates that one truck, one engine, and one ambulance were called to the scene. This combination represents a balanced and effective response to many types of incidents that firefighters might encounter.

A truck provides specialized equipment for tasks such as aerial operations, while an engine is equipped with water and hoses to suppress fires. An ambulance ensures that medical needs can be addressed on-site or that victims can be quickly transported to a hospital if necessary. In many situations, especially involving emergencies like structure fires or multi-casualty incidents, having this specific mix of resources allows the fire department to effectively manage the complex dynamics of the scene.

While the other combinations of resources provide varying levels of support, the selection of one truck, one engine, and one ambulance aligns well with a typical emergency response framework aimed at maximizing efficiency and effectiveness in service provision. Thus, this option encapsulates a standard and strategic deployment of resources for such an incident.