Final answer:
The correct way to operate a fire extinguisher is by moving it side to side to cover the base of the fire effectively.
Step-by-step explanation:
When using a fire extinguisher, the correct motion to follow is side to side. This motion ensures that the extinguishing agent is spread across the base of the fire, which is essential for effectively putting out the fire. The aim is to sweep the extinguisher's nozzle or hose from one side of the base of the fire to the other, covering the area of the flames to extinguish them fully.