The function describes the volume, f$($x$),$ of a right circular cylinder of height $4$ feet and radius x feet. If the radius is changing, find the instantaneous rate of change of the volume with respect to the radius when the radius is $7$ feet. Leave answer in terms of $.$

Question $10$ options:

A$)$

$28$ cubic feet per feet

B$)$

$56$ cubic feet per feet

C$)$

$14$ cubic feet per feet

D$)$

$8$ cubic feet per feet