A $4 \mathrm{~kg}$ roller is attached to a massless spring of spring constant $k=100 \mathrm{~N} / \mathrm{m}$. It rolls without slipping along a frictionless horizontal road. The roller is displaced from its equilibrium position by $10 \mathrm{~cm}$ and then released. Its maximum speed will be

• Correct answer
  A

  $0.5 \mathrm{~m} \mathrm{~s}^{-1}$
• B

  $0.6 \mathrm{~m} \mathrm{~s}^{-1}$
• C

  $0.4 \mathrm{~m} \mathrm{~s}^{-1}$
• D

  $0.8 \mathrm{~m} \mathrm{~s}^{-1}$

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