You are an electrician working in a plant that uses programmable logic controllers to perform most of the logic for the motor controls.The plant produces highly flammable chemicals so the plcs use a 24 volt vdc output that is intrinsically safe in a hazardous area.You are having trouble with output modules of the plcs that are connected to dc control relays.The outputs are going bad at an unsually high rate and you suspect that spikes voltages produced by the relay coils are responsible.To test your theory,you connect an oscilloscope to an output that is operating a dc relay coil and watch the display when the plc turns the relay off.You discover that there is high voltage spike produced by the relay.What device would you use to correct this problem,and how would you install it?