The bob of a simple pendulum executes simple harmonic motion in water with a period r,while the period of oscillation of the bob is t_o in air. Neglecting frictional force of water and given that the density of the bob is $\left(\frac{4}{3}\right)\times 1000 \mathrm{kg}/{\mathrm{m}}^3$.What relationship between t and t_o is true?

• A

  $\mathrm{t} = {\mathrm{t}}_{\mathrm{o}}$

• B

  $\mathrm{t}=\frac{{\mathrm{t}}_0}{2}$

• C

  $\mathrm{t}=2{\mathrm{t}}_0$

• D

  $\mathrm{t}=4{\mathrm{t}}_0$