desktop Calculator Which of the following statements is true regarding fixed and variable costs? O Both costs are constant when considered on a per-unit basis. O Variable costs are constant in total, and fixed costs vary in total. Fixed costs are constant in total, and variable costs are constant per unit. OBoth costs are constant when considered on a total basis. Calculator Which of the following manufacturing costs is an indirect cost of producing a product? O commissions for sales personnel Ooil lubricants used for factory machinery O hourly wages of an assembly worker O memory chips for a microcomputer manufacturer