Final answer:
In case an electrode freezes to the workpiece during welding, the appropriate step is to increase the amperage to help melt the frozen spot and release the electrode.
Step-by-step explanation:
If the electrode freezes to the work, the correct action to take is: a. Increase the amperage. By increasing the amperage, the temperature of the electrode will rise, which should help in melting the frozen spot and allowing the electrode to free itself. Using a chipping hammer to knock the electrode free can damage the electrode and the work surface. Changing the ground terminal is unlikely to solve the freezing issue, and turning off the welding machine immediately is not necessary unless there is a safety concern that cannot be otherwise addressed.