If `f(x)=x^n ,f(1)+(f^1(1))/1+(f^2(1))/(2!)+(f^n(1))/(n !),w h e r ef^r(x)` denotes the rth order derivative of `f(x)` with respect to `x ,` is `n` b. `2^n` c. `2^(n-1)` d. none of these