Information from the records of Conundrum Company for September was as follows: Sales Selling and administrative expenses Direct materials used Direct labor Variable factory overhead Factory overhead $307,500 52,500 66,000 75,000 50,000 51,250 Inventories Sept. 1 Sept 30 Direct materials $8,000 $10,500 Work in process 18,750 21,000 Finished goods 17,250 14,250 Conundrum Company produced 20,000 units. If production increased to 32,000 units next year, what is the effect on variable product cost per unit and total product cost per unit, respectively? Ca. remain the same, decrease b. remain the same; remain the same c. decrease; increase d. increase, remain the same