Choose the correct answer if θ is the angle between any two vectors $\overrightarrow a$ and $\overrightarrow b$, then $| \overrightarrow a ⋅\overrightarrow b | \: = \: | \overrightarrow a \times\overrightarrow b |$ when θ is equal to

Question

\begin{array} {1 1} (A)\; 0 \quad &(B) \;\frac{\pi}{4} \quad &(C)\; \frac{\pi}{2} \quad &(D) \;π \end{array}