Which of the following limits is equal to f/ (x ) (i.e. derivative of f), where f(x) - V x2 4 1 - 2x A Vh2 +1 -1-2h lim h-0 h V( + h)2 +1 - 2h lim h Vath)241 - Vx2 +1 - 2h lim h-0 h V(x 4 h)241-2x lim h 0 h O lim Va +1- 2x