Consider an Industry in Which, for Each Individual Firm in the Industry

Consider an industry in which, for each individual firm in the industry, cost per unit of output declines as the individual firm's output increases. As the size of the market increases, the average total cost at each firm

A) decreases because each firm produces more.
B) decreases because each firm produces less.
C) increases because each firm produces less.
D) increases because each firm produces more.
E) remains the same because the number of firms remains constant.