State the Period of the Function $$y = - 4 \sec \frac { \pi x } { 4 }$$

Multiple Choice

State the period of the function. $$y = - 4 \sec \frac { \pi x } { 4 }$$

A) $\frac { \pi } { 4 }$
B) 8
C) 10
D) $8 \pi$
E) 14