Compute the derivative of the function $()=$tan$(2+1)$f$($x$)=$tan$(2$x$+1).$

Select one:

a$.$

sec$2(2+1)$sec$2(2$x$+1)$

b$.$

$2$sin$2(2+1)2$sin$2(2$x$+1)$

c$.$

$2$sec$2(2+1)2$sec$2(2$x$+1)$

d$.$

$2$sec$2(2+1)$