$\lim\limits_{x\to 0}\large\frac{x(1+a\cos x)-b\sin x}{x^3}$$=1$ then $a,b$ are

Question

$\begin{array}{1 1}(A)\;\large\frac{1}{2},\frac{-3}{2}&(B)\;\large\frac{5}{2},\frac{3}{2}\\(C)\;\large\frac{-5}{2},\frac{-3}{2}&(D)\;\text{None of these}\end{array}$