The level of inventory of a manufactured product has increased by 7,520 units during a period. The following data are also available: Variable Fixed Unit manufacturing costs of the period $14.00 $6.00 Unit operating expenses of the period 2.00 2.00 The effect on operating income if variable costing is used rather than absorption costing would be a(n) Oa. $60,160 decrease Ob. $45,120 increase Oc. $60,160 increase Od. $45,120 decrease