The answer is D but I don't know how to get to the answer. Thank you

17. The schedule below shows tbc rti9!Einal cost ofa fitm ina rfectl com itive market Out ut units Ma inalcost S 7 3 S 6 65 7 6 8 9 05 8 Suppose the fixed cost decreases by SS hlle thc marginal cost for each unit of the output while the profit of increases by $2, As a result, the profit-maximiztng output of the firm the firm, A. B. C increases increases decreases decreases decreases may increase or decrease decreases .may ancrease or decrease