The feasible region for a linear program is defined by these three constraints: 5A + 5B 400; -1A + 1B 10; 1A + 3B 90; A 0; B 0. In this feasible region, the objective function (A - B) is maximized. Which of the following statements is true?

A. (35, 45) is the best corner point for this objective function (A - B).

B. The optimal objective value is 70.

C. (15, 25) is the best corner point for this objective .

D. The feasible region has 4 corner points all of which are equally good for this objective function.