4 The following table shows the demand curve and cost information for a firm that is a monopoly. Price Quantity TC $10 0 $500 $9 200 $1,000 $8 400 $1,600 $7 600 $2,500 $6 800 $4,000 What quantity should the firm produce to maximize profits? AO 200 units BO 800 units CO 400 units DO 600 units