Which of the following is considered an AHA?

Citric acid is classified as an alpha hydroxy acid (AHA), which is primarily derived from fruits and is widely used in skincare formulations for its exfoliating properties. AHAs are known for their ability to promote cell turnover, improve skin texture, and enhance overall radiance. They work by loosening the bonds between dead skin cells, allowing them to be shed more easily, which can lead to smoother skin and a reduction in the appearance of fine lines and dullness.

Tartaric acid, also an AHA, shares similar functions as citric acid but is not the correct answer according to the choice provided. Salicylic acid, on the other hand, is a beta hydroxy acid (BHA) rather than an AHA. BHAs are more oil-soluble and are effective for treating acne and blemishes. The mention of salts does not refer to any fruit-derived acids and therefore cannot be categorized as an AHA.

The focus on citric acid as the correct choice highlights its prominent role in the group of AHAs and its effective application in skincare.