Variable Cost Is

Variable cost is

A) the sum of the expenses of the firm that are stable and do not change with the quantity of a product that is produced and sold.
B) the sum of the expenses of the firm that change with the quantity of a product that is produced and sold.
C) the total expense incurred by a firm in producing and marketing a product, which equals the sum of fixed cost and marginal cost.
D) the average amount of money received for selling one unit of a product or simply the price of that unit.
E) the change in total cost that results from producing and marketing one additional unit of a product.