Perform a first derivative test on the function $f(x)=\sqrt[\phantom{2}]{x}ln7x$;$(0,).$

a$.$ Locate the critical points of the given function.

b$.$ Use the First Derivative Test to locate the local maximum and minimum values.

c$.$ Identify the absolute maximum and minimum values of the function on the given interval $($when they exist$).$

a$.$ Locate the critical points of the given function. Select the correct choice below and, if necessary, fill in the ansv

A$.$ The critical point$($s$)$ is$/$are at $x=$

$($Type an exact answer in terms of $e.)$

B$.$ There are no critical points.