A uniform rope of length $L$ and mass $m_1$, hangs vertically from a rigid support. A block of mass $m_2$ is attached to the free end of the rope. A transverse pulse of wavelength ${\lambda }_1$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is ${\lambda }_2$. The ratio ${\lambda }_2/{\lambda }_1$ is:

1. A
   $\sqrt{\frac{m_1+m_2}{m_2}}$
2. B
   $\sqrt{\frac{m_2}{m_1}}$
3. C
   $\sqrt{\frac{m_1+m_2}{m_1}}$
4. D
   $\sqrt{\frac{m_1}{m_2}}$