Treating this as a two-item checklist, addressee present and both verbs correctly backshifted, and scoring each option against it makes the comparison explicit rather than descriptive.
Running this two-point check across all four options shows that only one clears both requirements at once.
Therefore, the correct answer is She told her friend that she knew where was everyone.
Poetic Devices: Identify the poetic device used in the following line: "The wind whispered through the trees."