When preparing to suction a patient, which of the following…

When preparing to suction a patient, which of the following should be done? I. Set the vacuum control to FULL II. Screw the 500-mL collection bottle tightly onto the vacuum connector III. Attach 3 feet of vacuum tubing to the tubing connector on the collection jar IV. Pinch closed the vacuum tubing when the vacuum is turned on to measure the vacuum level