For the Simple Harmonic Motion Described by the Trigonometric Function,find $d = \frac { 1 } { 16 } \cos 12 \pi t$

Multiple Choice

For the simple harmonic motion described by the trigonometric function,find the frequency per second.? $d = \frac { 1 } { 16 } \cos 12 \pi t$ ?

A) 16 ?
B) ? ?
C) 12
D) 2?
E) 6