What best describes a comedone?

A comedone is best described as a clogged pore. It forms when the hair follicle becomes obstructed with a combination of sebum (oil) and dead skin cells. This blockage can result in two types of comedones: open comedones, commonly known as blackheads, and closed comedones, referred to as whiteheads. Both types involve the same underlying issue of pore blockage, which is a key characteristic distinguishing comedones from other skin lesions.

The other options describe different skin conditions: a raised lesion may refer to various types of skin elevations such as papules or plaques, an inflamed pustule is indicative of an acne lesion with redness and pus, and a red spot could refer to a range of skin issues, including irritation or inflammation. None of these capture the specific definition of a comedone as effectively as recognizing it as a clogged pore.