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)