If $f(x)=(x-3)^{9}+\left(x-3^{2}\right)^{4}+\ldots .+\left(x-3^{4}\right)^{5}$, then
(A) $f(x)$ is always increasing
(B) $f(x)=0$ has one real $\&$ eight imaginary roots
(C) $x=3,3^{2} \quad 3^{9}$ are the roots of $f(x)=0$
(D) $f(x)=0$ has a negative real root