11. Refer to the following table. Output Total variable cost($) Total cost($) 0 100 100 200 2 140 240 190 290 250 350 320 420 400 500 490 590 OO 590 690 If the firm can sell all units of output at a constant price of $70, how many units will be sold to maximize profit? (A) O (B) 5 (C) 7 (D) 6 (E) 2