[9.10.] Consider a competitive firm with a production function f:

? with n inputs, each of which costs w, per unit, thatproduces two outputs that are priced at pi, with quantity qi,i = 1,2. A regulator is concerned with the firm producing too little andhence imposes a penalty for producing quantity less than Qi； specifically, the penaity for underproduction of output i isλi (Qt - qi)(i.e., the firm pays this amount if it produces less than Qi). Let w be the vector of cost {w1, w2} and A be the vector of {λ1，λ2}

【題組】9. Which of the following statements are true?
(A) The firm's profit is concave in the vector w
(B)The firm's profit is convex in the vector w
(C)The firm's profit is both concave and convex in the vector w
(D)The firm's profit is neither concave nor convex in the vector w