State the Period of the Function $$y = \frac { 1 } { 2 } \sec \frac { \pi x } { 3 }$$

Multiple Choice

State the period of the function. $$y = \frac { 1 } { 2 } \sec \frac { \pi x } { 3 }$$

A) 10
B) 6
C) $\frac { \pi } { 3 }$
D) $6 \pi$
E) 8