Which of the following limits is equal to f (x) (i.e. derivative of f), where f(x) = Vx- +1 -2x Vh2 + 1 - 1 - 2h lim h-0 h O V (x + h)2+ 1-2h lim h-0 h O lim V(x + h)2 + 1 - Vx2 + 1 -2h h-0 h O V (x + h)2+ 1-2x lim h-0 h -2