A physical exfoliant is defined by its ability to physically scrub away dead skin cells from the skin's surface. This type of exfoliant often contains granules or particles that are textured and abrasive, allowing for mechanical action when applied. Examples include scrubs made with sugar, salt, or crushed seeds. By physically removing the buildup of dead skin, physical exfoliants can help to reveal smoother and more radiant skin underneath.
In contrast, chemical exfoliants use acids or enzymes to dissolve the bonds between dead skin cells, leading to a gentler form of exfoliation without the need for scrubbing. Enzymatic exfoliants specifically rely on natural enzymes to break down dead skin, while hydrating exfoliants typically focus on moisture rather than exfoliation. Therefore, the defining characteristic that sets the correct answer apart is its mechanical method of exfoliation, making physical exfoliants the right choice.