# If $\overrightarrow{a}$ and $\overrightarrow{b}$ are unit vectors and $|\overrightarrow{a} \times \overrightarrow{b}|=1$, then the angle between $\overrightarrow{a}$ and $\overrightarrow{b}$ is :
( A ) $\frac{\pi}{2}$
( B ) $\pi$
( C ) $\frac{\pi}{3}$
( D ) $\frac{\pi}{4}$