If $f: R \rightarrow R$ and $g: R \rightarrow R$ are defined by $f(x)=x-[x]$ and $g(x)=[x]$ for $x \in R$, where $[x]$ is the greatest integer not exceeding $x$, then for every $x \in R, f(g(x))$ is equal to

• A

  $x$
• Correct answer
  B

  $0$
• C

  $f(x)$
• D

  $g(x)$

Hence, the correct answer is option: 'B'.