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