What do the seatbelt exemptions for ambulance attendants and firefighters in the patient compartment or behind a fire truck's driver's cab have in common?

Correct answer: D. Both exemptions apply specifically where the person's actual work activities make wearing a seatbelt impracticable

Both exemptions in Regulation 613 hinge on the same condition: they apply where the performance of the person's work activities (attending to a patient, or a firefighter's duties behind the driver's cab) makes it impracticable to wear a seatbelt assembly — the exemption isn't a blanket pass for the job title, it's tied to the actual work making a seatbelt impractical in that moment.

Source: MTO Driver's Handbook: R.R.O. 1990, Regulation 613 (Seat Belt Assemblies) — ambulance attendants and firefighters