Which of the following is not one of the variables that shift market demand

Turtle corporation produces and sells a single product. data concerning that product appear below: per unit percent of sales selling price $ 150 100 % variable expenses 75 50 % contribution margin $ 75 50 % the company is currently selling 5,600 units per month. fixed expenses are $194,000 per month. the marketing manager believes that a $5,300 increase in the monthly advertising budget would result in a 190 unit increase in monthly sales. what should be the overall effect on the company's monthly net operating income of this change?