Correct Answer - Option 4 :
\(\sqrt {\frac{{{{\rm{k}}_2}}}{{{{\rm{k}}_1}}}}\)
As this is a case of simple harmonic motion
Maximum velocity is given by: \({v_{max}}\; = \;A\omega\) where A is the amplitude of oscillation.
\(\omega \; = \;\sqrt {\frac{k}{m}} \;\)
Here \({\left( {{V_{max}}} \right)_1}\; = \;{\left( {{V_{max}}} \right)_2} \Rightarrow {A_1}{\omega _1}\; = \;{A_2}{\omega _2}\)
\(\frac{{{A_1}}}{{{A_2}}}\; = \;\frac{{{\omega _2}}}{{{\omega _1}}}\; = \;\sqrt {\frac{{{k_2}}}{{{m_2}}}.\frac{{{m_1}}}{{{k_1}}}} \; = \;\sqrt {\frac{{{k_2}}}{{{k_1}}}} \;\)