Use the Two-Stage Method to Solve $z=4 x_{1}+6 x_{2}$ Subject To $2 x_{1}+x_{2}=12$

Use the two-stage method to solve.
-Maximize $z=4 x_{1}+6 x_{2}$
Subject to: $2 x_{1}+x_{2}=12$
$2 \mathrm{x}_{1}+2 \mathrm{x}_{2} \geq 20$
$2 \mathrm{x}_{1}+2 \mathrm{x}_{2} \leq 24$
$x_{1} \geq 0, x_{2} \geq 0$

A) Maximum is 72 for $x_{1}=0, x_{2}=12$
B) Maximum is 68 for $x_{1}=2, x_{2}=10$
C) Maximum is 56 for $x_{1}=2, x_{2}=8$
D) Maximum is 48 for $\mathrm{x}_{1}=12, \mathrm{x}_{2}=0$