Final answer:
To stop arc blow in welding, the most effective method is to turn off the machine and reestablish the ground connection by removing and then re-clamping the ground clamp.
Step-by-step explanation:
The question pertains to the problem of arc blow, which is a distortion of the electric arc during welding caused by various factors such as magnetic fields. To stop arc blow from occurring, the most appropriate action from the provided options would be (b) Turn off the machine, remove the ground clamp momentarily then clamp it back on. This is advisable because reestablishing the ground connection can reduce the magnetic field that causes the arc to deflect. Using different gloves or having the machine repaired will not directly solve an arc blow issue, and although switching electrodes might have some effect, reestablishment of the ground connection is a fundamental troubleshooting step.