Which of the following methods should a phlebotomist use to invert tubes to prevent clotting?

Shaking the tubes 4 to 8 times after collection.

Moving the tubes in a figure-eight motion 4 to 8 times after collection.

Rolling the tubes between the palms of the hands 4 to 8 times after collection.

Passing the tubes from hand to hand 4 to 8 times after collection.