Which of the following is a part of the sales commission formula?

The formula for calculating a sales commission is based on the sale price of an item and the commission rate that is applied to that sale price. When you multiply the sale price by the commission rate as expressed in a decimal format (for example, a 5% commission would be 0.05), you arrive at the total commission that is to be paid to the sales associate. This direct relationship highlights that the higher the sale price or commission rate, the greater the commission earned.

In contrast, the other options listed pertain to different calculations within finance or real estate that do not relate to the sales commission. For example, loan amount divided by property value refers to a loan-to-value ratio, which assesses risk in lending. Total monthly expenses divided by income calculates a financial ratio important for budgeting. Interest rate times loan duration helps determine the total interest paid over time but is outside the scope of how commissions are determined. Thus, the focus on the sale price and commission rate makes option A the essential component of the sales commission formula.