A small rock is tied to a massless string of length 5 \mathrm{~m}. The density of the rock is twice the density of the water. The rock is lowered into the water, while the other end of the string is attached to a pivot. Neglect any resistive forces from the water. The rock oscillates like a pendulum with angular frequency of which of the following?
Answer Choices
A. 1 \mathrm{rad} / \mathrm{s}
B. 0.7 \mathrm{rad} / \mathrm{s}
C. 0.5 \mathrm{rad} / \mathrm{s}
D. 1.4 \mathrm{rad} / \mathrm{s}
E. 2 \mathrm{rad} / \mathrm{s}