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. Based on this information: 1) Cos A is a mixed cost and Cost C is a variable cost 2) Cost B is a fixed cost and Cost A is a variable cost 3) Cost A is a mixed cost and Cost C is a fixed cost 4) Cost A is a fixed cost and Cost B is a variable cost