A mass M is suspended from a spring of negligible  mass . The spring is pulled a little and  then released so that the mass executes simple
harmonic motion with time period T. If the Mass is increased by ‘m’ then the time period becomes $\left(\frac{5\mathrm{T}}{4}\right)\text{ the ratio }\left(\frac{\mathrm{m}}{\mathrm{M}}\right)\text{ is }$

• A

  $\frac{9}{16}$

• B

  $\frac{25}{16}$

• C

  $\frac{16}{9}$

• D

  $\frac{4}{3}$