When discussing skin terminology, which combining form refers to that organ?

The combining form that refers to the skin is "cutane/o." In medical terminology, "cutane/o" originates from the Latin word "cutis," meaning skin. This combining form is often used in various medical terms related to the skin, such as "cutaneous," which pertains to the skin, and "cutaneous absorption," which refers to the absorption of substances through the skin.

The other options do not pertain specifically to the skin. "Erythem/o" relates to redness of the skin, often due to inflammation, but does not directly refer to the skin itself. "Diaphor/o" refers to sweating or perspiration, a physiological process rather than a direct reference to skin structure. "Cauter/o" involves burning or destroying tissue, which can include skin but does not embody the skin itself as an organ. Thus, "cutane/o" is the most accurate combining form for referring to the organ of the skin.