Priya is using a centrifuge in the lab as part of her experiment. What is the MOST important fire safety rule she should follow before using this piece of equipment?

A. Make sure the centrifuge is properly labeled.
B. Plug the centrifuge into a grounded, three-pronged outlet.
C. Don’t use the centrifuge if anyone else is in the lab.
D. Only use the centrifuge when it is placed on the floor.