The level of inventory of a manufactured product has increased by 8,158 units during a period. The following data are also available: The effect on operating income if absorption costing is used rather than variable costing would be a a. $89,738 increase b. $89,738 decrease c. $65,264 increase d. $65,264 decrease The level of inventory of a manufactured product has increased by 8,158 units during a period. The following data are also available: The effect on operating income if absorption costing is used rather than variable costing would be a a. $89,738 increase b. $89,738 decrease c. $65,264 increase d. $65,264 decrease