Which of the following is an example of a physical method of exfoliation that may use crystals to remove dead skin cells?

Microdermabrasion is a procedure that exemplifies a physical method of exfoliation. This technique involves the application of tiny crystals to the skin, which are used to buff away the outermost layer of dead skin cells. It works by physically abrading the skin, which helps to improve its texture and tone, and promotes cell turnover.

In contrast, enzymatic exfoliation relies on natural enzymes to dissolve dead skin cells, making it a different approach altogether. Chemical peels utilize acidic solutions to chemically remove the upper layers of the skin rather than physically scrubbing them off. Clay masks primarily work to absorb impurities and excess oil but do not have the same exfoliating properties as microdermabrasion. Thus, microdermabrasion stands out as the correct example of a physical exfoliation method that employs crystals for effective skin renewal.