Which of the following is not equal to $6x^2-24x -72$ ?

Question

$\begin{array}{1 1} (a)\; 6(x^2-4x-12) \\ (b)\; 6(x+2)(x-6) \\ (c)\; 6(x-2)(x+6) \\ (d)\; (6x+12)(x-6) \end{array}$