Sandy Robbins is the sole owner of a hair salon. He often takes small amounts of "lunch money" from the cash register, figuring that "it is my business anyway." His accountant, however, insists that Sandy make a note of the cash he takes, and at the end of the each accounting period, she debits owners' equity and credits the cash account for the total amount that Sandy has taken during the period. In recording the cash withdrawals even though Sandy is sole proprietor, the accountant is correctly applying the:

Matching concept

Entity concept

Materiality concept

Conservatism concept