The correct answer is C) either active or passive. Technicians servicing small refrigeration appliances are required to recover the refrigerant, and they can use either active or passive recovery equipment to do so. Active recovery equipment uses a compressor to remove the refrigerant from the system, while passive recovery equipment relies on the pressure differential to draw the refrigerant out without a compressor. Both types of equipment are approved for use in recovering refrigerants from small appliances. The other options are incorrect - technicians cannot use passive-only or active-only equipment, as they must be able to use whichever type of recovery equipment is appropriate for the specific appliance they are servicing. They also cannot simply vent the refrigerant, as that is not allowed under environmental regulations.