The Jackson Supply Company began its manufacturing operations on January 1, 2023. At the end of the year, the following information was available: Units manufactured..... Direct material costs Direct labor costs......... 25.000 $56,250 $77,500 -Variable overhead costs. $37.500 Fixed overhead costs...... $75,000 Units sold........ 15.000- Sales......... $270,000 Fixed selling costs.. $17,000 Fixed administrative costs. $13,000 Required: a. Calculate operating income using an absorption costing approach. b. Assuming absorption costing, what is the unit product cost? c. Calculate operating income using the variable costing approach. d. If variable costing is used, what is the unit product cost?