Simplify the expression fully and identify the necessary domain restrictions: $\frac{(x+2)(x-3)}{x^2-x-6}$

$1$, where $x\ne -2$, $3$

$1$, for all real numbers $x$

$\frac{(x+2)(x-3)}{(x+3)(x-2)}$, where $x\ne -3$, $2$

$0$, where $x\ne -2$, $3$