1. 8199. Which statement concerning a welding process is true? A. The inert-arc welding process uses an inert gas to protect the weld zone from the atmosphere. B. In the metallic-arc welding process, filler material, if needed, is provided by a separate metal rod of the proper material held in the arc. C. In the oxyacetylene welding process, the filler rod used for steel is covered with a thin coating of flux.