XYZ Company incurred the following costs for the month of August when it observed an activity level of 5,000 units: Variable costs $32,500; Fixed costs $25,000; Mixed costs $21,500; Total costs $79,000. During October, the activity level was 16,000 units, and the total costs incurred were $178,000. If the activity level were expected to be 8,000 units for the month of December, what amount of total costs would be expected? Select one: O a. $115,000 O b. $124,000 O c. $133,000 O d. $ 106,000 O e. None of the answers given