Which of the following is considered a characteristic of moderate acne?

The characteristic of moderate acne includes the presence of multiple inflamed pustules and some nodules. In the classification of acne severity, moderate acne is typically identified by the presence of various types of lesions—specifically, a combination of inflamed papules, pustules, and some nodular formations. This reflects a greater level of inflammation and potential pain compared to mild forms, which may only feature non-inflamed comedones.

In contrast, the other options describe conditions that either do not align with the definition of moderate acne or represent other stages of acne or skin condition. The presence of only comedones would indicate a milder form of acne rather than moderate. No visible lesions signify an absence of acne, which cannot be classified under any severity. Finally, the presence of severe scarring typically corresponds with severe acne, not moderate, since moderate cases generally don't lead to significant scarring. Thus, the defining traits of moderate acne include the observable symptoms outlined in the correct option.