Speed of electron in the ground state of hydrogen atom is ${\mathrm{V}}_0$ . Then speed of electron in the third  excited state of hydrogen atom is  ---

• A

  $\frac{{\mathrm{V}}_0}{4}$

• B

  $\frac{{\mathrm{V}}_0}{3}$

• C

  $4{\mathrm{V}}_0$

• D

  $9V_0$