Latest MBA Aptitude Question SOLUTION: f(x)=(x+n+1)(x+n+2).....(x+2n) where n is a fixed number.Find f'(n)

1) (2n)!
2) (2n)!(1/(n+1)!+1/(n+2)!+...+1/(2n)!)
3) (3n)!
4) (3n)!/(2n)!*(1/(2n+1)+1/(