A spring of force constant k is cut into two equal parts, and mass ‘m’ is suspended from parallel combination of the springs. Then frequency of small oscillations is

• A

  $\mathrm{f}=\frac{1}{2\mathrm{\pi }}\sqrt{\frac{\mathrm{K}}{\mathrm{m}}}$

• B

  $\mathrm{f}=\frac{1}{2\mathrm{\pi }}\sqrt{\frac{\mathrm{K}}{2\mathrm{m}}}$

• C

  $\mathrm{f}=\frac{1}{2\mathrm{\pi }}\sqrt{\frac{4\mathrm{K}}{\mathrm{m}}}$

• D

  $\mathrm{f}=\frac{1}{2\mathrm{\pi }}\sqrt{\frac{2\mathrm{K}}{\mathrm{m}}}$