The period of this function is
π / 4
8
2π
π / 2

ANSWER
[tex]\frac{\pi}{2} [/tex]
EXPLANATION
The period refers to the interval over which the function completes one full cycle.
The given function completed four cycles in on the the interval.
[-π,π]
The period is
[tex] = \frac{\pi - - \pi}{4} [/tex]
[tex]= \frac{\pi + \pi}{4} [/tex]
Simplify;
[tex]= \frac{2 \pi}{4} [/tex]
[tex]= \frac{\pi}{2} [/tex]
The last choice is correct.