Name a common exfoliating ingredient used in skincare.

Alpha Hydroxy Acids (AHAs) are widely recognized as common exfoliating ingredients in the skincare industry. They are water-soluble acids derived from fruits and milk, which help to exfoliate the skin's surface. By breaking down the bonds that hold dead skin cells together, AHAs facilitate the removal of these cells, leading to a smoother and more radiant complexion.

AHAs are particularly effective for improving skin texture, reducing the appearance of fine lines, and promoting an even skin tone. They can also enhance the skin’s ability to retain moisture and improve overall hydration levels, which is beneficial for maintaining a healthy appearance.

In contrast, glycerin is primarily a humectant used for moisturizing rather than exfoliating, while petrolatum and mineral oil serve as occlusive agents that help lock in moisture but do not provide exfoliating benefits. Therefore, AHAs stand out as the most appropriate option among the choices given for exfoliation in skincare routines.