3. There are three producers in the widget industry, with the following marginal cost curves: FirInA FiImB FirmC Q MC Q M C Q MC 1 $1 1 $3 1 Si? 2 2 2 {i 2 8 3 9 3 T 3 1'0 4 12 4 S 4 12 a) Suppose that the price of widgets is $3. How many widgets are produced alto- gether? What is the social marginal cost of producing those widgets? h) Suppose instead that for some reason, Firrn A can sell its widgeets for $12, Firm B can sell its widgets for $3, and Firm C can sell its widgets for $10. How roan}.r widgets are produced? What is the social variable cost of producing those widgets