For an electron in $2s$ and $2p$ orbitals,the orbital angular momentum values,respectively,are $:$

• A
  $\sqrt{2} \frac{h}{2 \pi}$ and $0$
• B
  $\frac{h}{2 \pi}$ and $\sqrt{2} \frac{h}{2 \pi}$
• C
  $0$ and $\sqrt{6} \frac{h}{2 \pi}$
• D
  $0$ and $\sqrt{2} \frac{h}{2 \pi}$