f(x) = ([x] + 1)/({x} + 1) for f: [0, 5/2) → (1/2, 3], where [ . ] represents greatest integer function and { . } represents fractional part of x , then which of the following is true.
(A) f(x) is injective discontinuous function.
(B) f(x) is surjective non-differentiable function.
(C) min [lim(x →1-)f(x), lim(x →1+) f(x)] = f(1)
(D) max (x values of point of discontinuity) = f(1)