The function $f(x)=3+2(a+1) x+\left(a^{2}+1\right) x^{2}-x^{3}$ has a local minimum at $x=x_{1}$ and local maximum at $x=x_{2}$ such that $\mathrm{x}_{1}<2<\mathrm{x}_{2}$ then a belongs to the interval(s)
(A) $\left(-\infty,-\frac{3}{2}\right)$
(B) $\left(-\frac{3}{2}, 1\right)$
(C) $(0, \infty)$
(D) $(1, \infty)$