Maximize $z= 15x+ 13 y $ subject to constraints $2x+ 3y ≤ 180, 4x ≤ 240, 6y ≤240 , x, y ≥0.$ Which of the following is true ?

(A) Feasible region is unbounded

(B) Feasible region is bounded

(C) Maximum value of $z=1160$

(D) Maximum value occurs at (60, 0)

(E) Maximum value occurs at (60, 20)

Choose the correct answer from the options given below :

(B), (C), (E) only