Submerged arc welding is a(an)_____ welding process.

Submerged arc welding (SAW) is indeed characterized as an AC or DC electric welding process. This technique involves creating an electric arc between the workpiece and a continuously fed electrode, which is submerged under a layer of granular flux. The flux serves multiple purposes: it protects the molten weld pool from atmospheric contamination, helps stabilize the arc, and can even contribute to the alloying elements of the weld.

In practice, submerged arc welding can be performed using either alternating current (AC) or direct current (DC) power sources. The choice between AC and DC may depend on factors like the type of material being welded, the thickness of the material, and the specific welding conditions. This flexibility in using both types of electric current further supports the accuracy of the correct answer, as it encompasses both possibilities.

This understanding provides insight into why other methods such as oxy-acetylene are not applicable in this context, as they do not involve an electric arc, nor do they use a submerged flux to facilitate the welding process. Rather, they rely on combustion of gases to produce the necessary heat for welding, which differs fundamentally from the principles behind submerged arc welding.