The magnetic susceptibility of the material of a rod is $499$. Permeability of vacuum is $4 \pi \times 10^{-7} \ H/m$. Absolute permeability of the material of the rod in $H/m$ is:

• A
  $\pi \times 10^{-4}$
• B
  $2 \pi \times 10^{-4}$
• C
  $3 \pi \times 10^{-4}$
• D
  $4 \pi \times 10^{-4}$