Compute the derivative of the function

f$($x$)=14$x$25$f$($x$)=14$x$25$

Select one:

a$.$

$44$x$2544$x$25$

b$.$

$4$x$(4$x$25)4$x$254$x$(4$x$25)4$x$25$

c$.$

$1(4$x$25)31(4$x$25)3$

d$.$

$124$x$25$