When a serum separation tube (SST) is collected, which of the following actions should the phlebotomist take to ensure optimal test results?

Invert the tube 5 to 8 times and then set for 30 minutes prior to centrifugation.

Invert the tube 1 to 3 times and then set for 1 hour prior to centrifugation.

Invert the tube 2 to 4 times and then set for 15 minutes prior to centrifugation.

Invert the tube 8 to 10 times and then set for 2 hours prior to centrifugation.