What is included in an MCI response?

The response that includes 4 engines, 2 trucks, Squad 1, 2 Battalion Chiefs (BCs), HS 18, and 1 ambulance represents a comprehensive approach to a Mass Casualty Incident (MCI). This selection encompasses a variety of resources that are essential for managing a high number of casualties effectively.

In an MCI, it's vital to have a substantial number of engines and trucks to ensure that there is sufficient firefighting capability while also providing immediate support for emergency medical services. The presence of multiple battalion chiefs allows for effective command and coordination, which is crucial during large-scale incidents to ensure that resources are directed appropriately and efficiently. Squad 1 indicates specialized units that may be trained to handle specific needs such as heavy rescue or technical assistance.

Having a dedicated ambulance is also critical for immediate patient transport, which is a significant aspect of responding to mass casualty situations. The combination of these resources in option B ensures a well-rounded response capable of managing both fire suppression and medical needs during an MCI.