Two bodies of masses $1 \mathrm{kg}$ and $4 \mathrm{kg}$ are connected to a vertical spring, as shown in the figure. The smaller mass executes simple harmonic motion of angular frequency $25 \mathrm{rad} {\mathrm{s}}^{-1}$, and amplitude $1.6 \mathrm{cm}$ while the bigger mass remains stationary on the ground. The maximum force exerted by the system on the floor is (take $g = 10 \mathrm{m} {\mathrm{s}}^{-2}$).

• A

  $20 \mathrm{N}$

   
• Correct answer
  B

  $60 \mathrm{N}$

   
• C

  $40 \mathrm{N}$

   
• D

  $10 \mathrm{N}$

   

Hence, the correct answer is option: 'B'.