Classify the following items as variable (V), fixed (F), or mixed (M): Rent for the factory building A)V B)F C)M Depreciation on production equipment A)V B)F C)M Production managers' salaries A)V B)F C)M Production workers' wages A)V B)F C)M Cost of materials used in production A)V B)F C)M Fire insurance for the plant A)V B)F C)M Sales commissions (3% of sales) A)V B)F C)M Sales managers' total compensation (salary + sales commissions) A)V B)F C)M