A block is in simple harmonic motion (S.H.M) on the end of the spring with position given by $x=(5) \cos \left(\omega t+\frac{\pi}{4}\right)$ If the total mechanical energy used is 100 J to achieve maximum displacement, then the potential energy at time t = 0 is

• A

  20 J
• B

  80 J
• C

  75 J
• Correct answer
  D

  50 J

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