Which personnel are authorized to respond to incidents?

The correct choice is that off-duty personnel who are close to the incident are authorized to respond. This is typically a standard protocol in emergency response systems, ensuring that trained personnel can provide immediate assistance when needed. When off-duty firefighters are nearby, their experience and training can be invaluable in managing emergency situations effectively. They can quickly integrate into the response efforts, utilizing their skills and knowledge to help control the situation, assist victims, or provide support to on-duty teams until more resources can be mobilized.

Retired firefighters, while experienced, are generally not authorized to respond to incidents unless specifically called upon in certain circumstances or under particular programs that the fire department may have in place. All off-duty personnel, as a broader category, do not have the same standing as those currently on duty or close to the incident, as some may not have the same level of readiness or ability to engage effectively. Volunteers typically have a role in specific programs or under specific conditions but do not have the same authorization or training as active-duty personnel responding to emergencies.