We Are to Minimize $p = 3 a + 2 b$

We are to minimize $p = 3 a + 2 b$ subject to the following constraints. $$\begin{array} { l } a + b \geq 4 \\3 a + b \geq 6 \\a , b \geq 0\end{array}$$
After using the simplex method for dual problem to arrive at the tableau below, what is the maximum value for $p$
X y s t p
$$\left[ \begin{array} { c c c c c } 0 & 1 & \frac { 1 } { 2 } & - \frac { 1 } { 2 } & 0 \\\frac { 1 } { 2 } & & & \\1 & 0 & - \frac { 1 } { 2 } & \frac { 3 } { 2 } & 0 \\\frac { 3 } { 2 } & & & & \\0 & 0 & 1 & 3 & 1 \\9 & & & &\end{array} \right]$$

A) 9
B) 3
C) 5.5
D) $\frac { 1 } { 2 }$
E) $\frac { 3 } { 2 }$