$A$ diatomic gas consisting of rigid molecules is at a temperature of $87^{\circ} C$. If the moment of inertia of the rotating diatomic rigid molecule is $2.76 \times 10^{-39} \text{ g cm}^2$,then the rms angular speed of the molecule is (Boltzmann constant $= 1.38 \times 10^{-23} \text{ J K}^{-1}$).

• A
  $6 \times 10^{12} \text{ rad s}^{-1}$
• B
  $3 \times 10^{12} \text{ rad s}^{-1}$
• C
  $6 \times 10^{13} \text{ rad s}^{-1}$
• D
  $3 \times 10^{13} \text{ rad s}^{-1}$