If $\theta$ is the angle between any two vectors $\overrightarrow {a}$ and $\overrightarrow {b}$ , then $|\overrightarrow {a} . \overrightarrow {b} | = |\overrightarrow {a} \times \overrightarrow {b}|$, then what is the value of $\theta$

Question

$(A)\; \frac{\pi}{2}$
$(B)\; \frac{\pi}{4}$
$(C)\; 0$
$(D)\; \frac{\pi}{3}$