The bob of a simple pendulum executes simple harmonic motion in water with a period t, while the period of oscillation of the bob is t₀ in air. Neglecting frictional force of water and given that the density of the bob is (4/3)×1000kg/m³. What relationship between t and t₀ is true?
a. t=t₀
b. t=t₀/2
c. t=2t₀
d. t=4t₀