Which of the following is the English equivalent of "Klebstoff"?

The term "Klebstoff" in German directly translates to "adhesive" in English. An adhesive is a substance used for bonding objects together, which perfectly aligns with the function described by "Klebstoff." This is a more technical term that encompasses various types of bonding agents, including glue, tape, and other similar substances.

While "glue" is a common synonym, it is a narrower term that refers specifically to a certain type of adhesive, typically based on a liquid form that hardens. "Material" does not relate directly to adhesives, as it refers to the substance from which things are made rather than agents for bonding. "Finish" typically pertains to the surface treatment or coating on a material rather than a bonding agent. Thus, "adhesive" is the most appropriate and precise English equivalent for "Klebstoff."