If $f :IR \to IR$ is defined by $f(x) =\bigg[\large\frac{x}{5}\bigg]$ for $ x \in IR,$ Where $[y]$ denotes the greatest integer not exceeding y, then $ (f(x):|x| < 71)=$

Question

\[\begin {array} {1 1} (a)\;\{-14,-13,......,0,.......,13,14\}\\ (b)\;\{-14,-13,......,0,.......,14,15\}\\ (c)\;\{-15,-14,......,0,.......,14,15\} \\ (d)\;\{-15,-14,......,0,.......,13,14\} \end {array}\]