Under what condition is an ambulance driver in Alberta legally permitted to run a red traffic light?

1. Whenever they are on shift and returning to the station
2. Only when responding to an emergency call, with emergency lights and siren activated, and after stopping or slowing down to ensure it is safe to proceed
3. Whenever they want, as emergency vehicles have absolute priority in all circumstances
4. Only if they are driving under 30 km/h and flashing their high beams