Which of the following is a benefit of using the negative pole during galvanic treatment?

Using the negative pole during galvanic treatment provides a specific benefit related to skin physiology. When the negative pole is applied, it generates a reaction that helps to expand the pores temporarily. This expansion makes it easier for treatment products to penetrate the skin, allowing for deeper cleansing and enhanced efficacy of subsequent products applied during the treatment.

The negative pole also has a calming effect on the skin, often resulting in reduced inflammation and redness, which can also contribute to the perception of enhanced absorption. It's important to note that while other options may present benefits associated with different types of treatments or poles, they do not specifically relate to the primary function of the negative pole in galvanic treatment. Thus, the ability to aid in the expansion of pores is a key advantage of using this technique during facial treatments.