Let f : (4, 6) → (6, 8) be a function defined by $\mathrm{f}\left(\mathrm{x}\right)=\mathrm{x}+\left[\frac{\mathrm{x}}{2}\right]$ (where [ ⋅ ] denotes the greatest integer function), then f ^{– 1} (x) is equal to

• A

  $\mathrm{x}-\left[\frac{\mathrm{x}}{2}\right]$

• B

  – x – 2

• C

  x – 2

• D

  $\frac{1}{\mathrm{x}+\left[\frac{\mathrm{x}}{2}\right]}$