Which groups are exempt from the regulation of speed for emergency vehicles?

The correct answer identifies that police and physicians are exempt from speed regulations for emergency vehicles. This is rooted in the specific roles these professionals have during emergencies.

Police officers are granted the ability to exceed posted speed limits when responding to emergencies as part of their duty to maintain public safety and enforce the law. They often are the first responders to incidents and need to arrive quickly.

Physicians, particularly those who are on call, may also respond to emergencies and are recognized for the critical nature of their role in providing immediate medical assistance. In some jurisdictions, when they are responding to emergencies, they can be exempt from certain traffic laws, including speed regulations.

In contrast, while firefighters, paramedics, ambulances, and rescue units are indeed emergency responders and may have similar exemptions, the question focuses on specific groups rather than a blanket exemption encompassing all emergency personnel, which is reflected in the answer given.