Answer: Percentage-of-sales method
Step-by-step explanation:
The percentage of the sales method is refers to the developing the budgeting financial statement that used in the business for predicting the overall growth of the sales in an organization annually.
This method is also known as the financial forecasting method that uses the data for predicting the financing amount for accomplishing the goals of an organization.
According to the given question, the owner is using the percentage-of-sales method for determine the budget for the restaurant advertisement.
Therefore, Percentage-of-sales method is the correct answer.