For any two non-zero complex numbers $z_1$ and $z_2$, if $\left|z_1+z_2\right|^2=\left|z_1\right|^2+\left|z_2\right|^2$, then

• Correct answer
  A

  $\operatorname{Re}\left(\frac{z_1}{z_2}\right)=0$
• B

  $\operatorname{Im}\left(\frac{z_1}{z_2}\right)=0$
• C

  $\operatorname{Re}\left(z_1 z_2\right)=0$
• D

  $\operatorname{Im}\left(z_1 z_2\right)=0$

Hence, the correct answer is option: 'A'.