Le Chteau Joyal is an historic hotel in the heart of old Quebec City. It is owned by Riel Hotels, which operates additional properties in Halifax, Montreal, and Winnipeg. Le Chteau Joyal has 9 floors, with approximately 20 rooms per floor. Facilities also include a workout room, restaurant, and pool. The hotel is organized into 5 departments: front desk, engineering, housekeeping, food \& beverage, and customer relations. As part of its operation, Le Chteau Joyal regularly incurs the following costs: General manager's salary Housekeeping supplies Utility costs Amortization on workout room equipment Advertising Food and beverage costs Amortization on restaurant equipment Which cost listed above is most likely to be a customer-sustaining cost? Amortization on workout room equipment Utility costs Housekeeping supplies General manager's salary