Which of the following is part of situational response for reaction forces?

The role of reaction forces in situation response is primarily focused on immediately addressing incidents, threats, or emergencies in various environments. Responding to buildings and ships encompasses a range of security challenges, including intrusions, emergencies, or potential attacks, where a rapid and tactical response is essential. This aspect emphasizes the physical presence and action of reaction forces in critical situations, making it essential for maintaining safety and security in diverse locations.

The other choices, while important within the broader framework of security operations, are not as closely associated with the immediate, tactical responses required from reaction forces during a situation. Writing reports, coordinating with management, and providing customer service tend to be more administrative or support tasks, which, although necessary for overall operational effectiveness, do not capture the core function of a reaction force in situational response. Thus, responding directly to threats in specific environments represents the primary and most urgent responsibility of a reaction force, highlighting why this choice is the most fitting for the question.