If $\alpha$ is a repeated root of $ax^2+bx+c=0$, then $\lim\limits_{x\to \alpha}\large\frac{\sin(ax^2+bx+c)}{(x-\alpha)^2}$ =

Question

$(a)\;0\qquad(b)\;a\qquad(c)\;b\qquad(d)\;c$