Delta sonic, a chain of full service automotive detailers, is considering introducing a new 15-minute car wash and wax service at one of its locations. the firm expects that sales from the new 15-minute service will be $175,000 per year. delta sonic currently offers a 1-hour wash/wax/detail service with annual sales of $90,000. while many of the 15-minute sales will be to new customers, delta sonic estimates that 40% of their 1-hour customers will switch and use the 15-minute service. the level of incremental sales associated with introducing the new 15-minute wash/wax service is closest to o a. $70,000 o b. $36,000 oc. $175,000 od. $85,000 e $139,000