During the process of Refrigerant Recovery, the Technician should operate the recovery unit until the system pressure has been reduced to a vacuum, then ______________.

A. Immediately close the valve in the service lines and remove the lines from the vehicle

B. Immediately close the valve in the service line and charge the system

C. *Recover to a vacuum of 4 inches of mercury, isolate the system and wait 5 minutes to see that the system holds the vaccum

D. Open the shut­off valves which must be located within 4 inches of the service ends