Let $f(x)=x^{3}-3(7-a) x^{2}-3\left(9-a^{2}\right) x+2$
The values of $\mathrm{a}$, if $\mathrm{f}(\mathrm{x})$ has a positive point of local maxima, are
(A) $\phi$
(B) $(-\infty,-3) \cup(3, \infty)$
(C) $\left(-\infty, \frac{58}{14}\right)$
(D) None of these