Tawny Kitain, Ltd. incurs three costs in its operations. Information related to these costs, expressed as the total costs at two different production levels, is presented below: 1,000 units $10,000 2,000 units $15,000 Cost A $21,000 $21,000 Cost B $16,000 $32,000 Cost C Which of these costs are variable (not mixed or fixed)? conly bonly a, b, and c a and c Question 8 1 pts Which of the following increases when the activity level decreases? total variable costs variable costs per unit fixed costs per unit total fixed costs