Assume the price for a purely competitive firm is $48. TP AFC AVC ATC MC 0 ------ ------- -------- ------- 1 $60 $45 $105 $45 2 $30 $42.50 $72.50 $40 3 $20 $40 $60 $35 4 $15 $37.50 $52.50 $30 5 $12 $37.00 $49.00 $35 6 $10 $37.50 $47.50 $40 7 $8.57 $38.57 $47.14 $45 8 $7.50 $40.63 $48.13 $55 What is the optimal quantity? a. 3 units b. 5 units c. 7 units d. 8 units