For what value of x, if any is $\large\frac{(4-2x)(x-6)}{(6+3x)}$ undefined?

Question

$\begin{array}{1 1} (a)\;2 \\ (b)\;-2 \\ (c) \;\large\frac{1}{2} \\ (d)\;\large\frac{1}{2} \end{array}$