For the linear programming problem (LPP), the objective function is Z = 4x + 3y and the feasible region determined by a set of constraints is shown in the graph:

Which of the following statements is true?
(A) Maximum value of Z is at R(40, 0).
(B) Maximum value of Z is at Q(30, 20) .
(C) Value of Z at R(40, 0) is less than the value at P(0, 40).
(D) The value of Z at Q(30, 20) is less than the value at R(40, 0).