$\mathrm{A} C D$ Has a Diameter Of $12.0 \mathrm{~cm}$ If The Has

Multiple Choice

$\mathrm{A} C D$ has a diameter of $12.0 \mathrm{~cm}$ . If the $\mathrm{CD}$ is rotating at a constant frequency of $3.18 \mathrm{~Hz}$ , then the period of the rotational motion is

A) $0.441 \mathrm{~s}$ .
B) $0.582 \mathrm{~s}$ .
C) $0.698 \mathrm{~s}$ .
D) $0.750 \mathrm{~s}$ .
E) $0.314 \mathrm{~s}$ .