Compute the derivative $of$ the function

$f(x)=\frac{(x^2-x{)}^3(3x+1)}{x^4+2x^2-1}$

Select one:

$a.$

$b.\frac{(x^2+2x^2-1)3(x^2-x{)}^2(2x-1)(3x+1)-(x^2-x{)}^3(3x+1)(4x^3+4x)}{(x^4+2x^2-1{)}^2}$

$c.$

$d.\frac{3(x^4+2x^2-1)(x^2-x{)}^3-(x^2-x{)}^3(3x+1)(4x^3+4x)}{(x^4+2x^2-1{)}^2}$