What is the purpose of the contact tip in MIG welding?

The contact tip plays a crucial role in MIG welding as it is responsible for transferring the welding current directly to the filler wire. This is essential for creating the arc that melts the wire and base metals, allowing for effective fusion during the welding process. The contact tip must maintain a good electrical connection with the filler wire, ensuring that sufficient current flows through. This enables a stable and efficient arc, which is central to achieving the desired weld quality.

While other components of the MIG welding system are important, such as those that may protect the weld area or regulate gas flow, the primary function of the contact tip is directly related to the transfer and control of welding current, making option C the correct choice in this context.