Final answer:
Paramedics should wait behind the stopped traffic with emergency equipment activated until the pathway is cleared to proceed safely to the cardiac arrest incident.
Step-by-step explanation:
When paramedics are responding to a cardiac arrest with lights and sirens and come upon a red light with stopped traffic and no safe route to bypass, the most appropriate action would be to keep the emergency equipment activated and wait behind the vehicles until the pathway is clear. This option maintains the safety of all road users, including the emergency responders. While it is critical to reach the patient as soon as possible during a cardiac arrest, it is also essential to ensure that the approach to the intersection does not create additional emergencies or accidents.