Check the injectivity and surjectivity of the following functions: $f : Z\to Z \;given\; by\; f(x)\; = x^2$

Question

  A) $f$ is injective and surjective B) $f$ is injective only C) $f$ is surjective only D) $f$ is neither injective nor surjective     Note: This is part 2 of a 5  part question, split as 5 separate questions here.