The ratio of the time periods of a simple pendulum at heights $2 R_E$ and $3 R_E$ from the surface of the earth is ( $R_E$ is radius of the earth)

• A

  $1: 2$
• B

  $1: 3$
• Correct answer
  C

  $3: 4$
• D

  $2: 3$

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