A block is suspended by a spring and the elongation of the spring is found to be 10 cm. The block is now pulled downward by further 5 cm and released. Then frequency of oscillation of the block is (Take g = 10 m/s²)

• A

  $\raisebox{1ex}{$5$}\!\left/ \!\raisebox{-1ex}{$\mathrm{\pi }$}\right.\mathrm{Hz}$

• B

  $\raisebox{1ex}{$\text{10}$}\!\left/ \!\raisebox{-1ex}{$\text{π}$}\right.\text{\hspace{0.33em}Hz}$

• C

  $\raisebox{1ex}{$\text{4}$}\!\left/ \!\raisebox{-1ex}{$\text{π}$}\right.\text{\hspace{0.33em}Hz}$

• D

  $\raisebox{1ex}{$\text{5}$}\!\left/ \!\raisebox{-1ex}{$\text{2π}$}\right.\text{\hspace{0.33em}Hz}$