Final answer:
The correct time to remove the tourniquet during a venipuncture is after locating and accessing the vein successfully.
Step-by-step explanation:
The correct time to remove the tourniquet during a venipuncture is after locating and accessing the vein successfully. The tourniquet is initially applied to the patient's arm to create venous congestion and make the vein more visible and accessible for the venipuncture procedure. However, once the vein has been accessed and blood flow has been established, the tourniquet should be released and removed to restore normal blood circulation in the patient's arm.