Find the Maximum Value of the Objective Function and Where $\left( \frac { 22 } { 3 } , \frac { 19 } { 6 } \right)$

Multiple Choice

Find the maximum value of the objective function and where it occurs,subject to the constraints: ?
Objective function:
?
Z = 12x + 24y
?
Constraints:
?
X ? 0
Y ? 0
X + 4y ? 20
X + y ? 18
?2x + 2y ? 21
?

A) Maximum at (0,5) : 120
B) Maximum at $\left( \frac { 22 } { 3 } , \frac { 19 } { 6 } \right)$ : 164
C) No maximum
D) Maximum at $\left( \frac { 21 } { 2 } , 0 \right)$ : 126
E) Maximum at (0,0) : 0