Data for Cost A and Cost B appear below: Units Produced Cost Per Unit Total Cost Cost A 1 ? $10 10 ? $100 100 ? $1,000 1,000 ? $10,000 Cost B $5,000 ? ? 10 $500 100 $50 ? 1,000 $5 ? Which of the above best describes the behavior of Costs A and B? Cost A is variable, Cost B is fixed Cost A is fixed, Cost B is variable Both Cost A and Cost B are fixed Both Cost A and Cost B are variable