If \( z_{1} \) and \( z_{2} \) are two non-zero complex numbers, su...

If \( z_{1} \) and \( z_{2} \) are two non-zero complex numbers, such that \( \left|z_{1}+z_{2}\right|=\left|z_{1}\right|+\left|z_{2}\right| \), then \( \arg \left(z_{1}\right)-\arg \left(z_{2}\right) \) is
\( \mathrm{P} \) equal to
[AIEEE 2005, 3M]
W
(a) \( -\pi \)
(b) \( -\pi / 2 \)
(c) \( \pi / 2 \)
(d) 0