Solve this:

49.  When a mass is attached to a spring, its length is increased by 20 cm. It is further lowered and released. The time period of its S.H.M is
 
$$\begin{gathered} \left(A\right) 2\mathrm{\pi }/7 \sec \left(\mathrm{B}\right) 2\mathrm{\pi } \sec \\ \left(\mathrm{C}\right) 4\mathrm{\pi } \sec \left(\mathrm{D}\right) \mathrm{data} \mathrm{is} \mathrm{not} \mathrm{enough} \end{gathered}$$