The solution of the system of three inequalities is given by a polygonal convex set.

8x + 2y ≥ 36

-3x + 6y ≤ 27

-7x + 5y ≥ -18

The function f(x,y) = 9x + 5y passes through this set. What values of (x,y) give f(x,y) its maximum value?

A)(-3, 2)

B)(-3, 6)

C)(9, 9)

D)(8, 2)