Consider the Function $$y = \cos 3 x$$ Specify the Period

Multiple Choice

Consider the function $$y = \cos 3 x$$ . Specify the period.

A) $$\frac { \pi } { 3 }$$
B) $$\frac { 2 \pi } { 3 }$$
C) $$\frac { 6 \pi } { 7 }$$
D) $$2 \pi$$
E) $$- \frac { 2 \pi } { 3 }$$