The following chart shows three different costs: Cost A, Cost B, Cost C. For each cost, the chart shows the total cost and cost per unit at two different volumes within the same relevant range. At 4,000 units Total cost Cost per Unit Total cost At 6,000 units Cost per Unit Cost A $ 12.000 $3.00 $12,000 $2.00 Cost B $12,000 $3.00 $15,000 Cost C $12,000 $3.00 $18,000 $2.50 $3.00 Based on this information: 1) Cost B is a fixed cost and Cost A is a variable cost 2) Cost A is a mixed cost and Cost C is a variable cost 3) Cost A is a fixed cost and Cost C is a variable cost 4) Cost A is a fixed cost and Cost B is a variable cost