Let $f(x)=a x^{5}+b x^{4}+c x^{3}+d x^{2}+e x$, where $a, b_{1} c, d, e \in R$
and $f(x)=0$ has a positive root $\alpha$, then
(A) $\mathrm{f}(\mathrm{x})=0$ has root al such that $0<\alpha_{1}<\alpha$
(B) $\mathrm{f}^{\prime}(\mathrm{x})=0$ has at least one real root
(C) $\mathrm{f}^{\prime}(\mathrm{x})=0$ has at least two real roots
(D) All of the above