Evaluate $\underset{x}{lim}f(x)$ and $\underset{x-}{lim}f(x)$ for the following function. Then give the horizontal asymptote of $f($if any$).$

$f(x)=\frac{\sqrt[3]{x^{6}729}}{4x^2\sqrt[\phantom{2}]{5x^{4}49}}$

Evaluate $\underset{x}{lim}f(x).$ Select the correct choice and, if necessary, fill in the answer box to complete your choice.

A$.\underset{x}{lim}f(x)=$

$($Type an exact answer, using radicals as needed.$)$

B$.$ The limit does not exist and is neither $$ nor $-.$