What vs Who

Bonjour Patricia,
I am unable to locate the question in the kwiz that you are referring to; however, it is very possible that there is an incorrect question I know the team is quite appreciative to you for pointing this out as it helps them tremendously.
In the meantime, here are a couple of locutions with their respective translations:
qu'est-ce que --> that is what
qu'est-ce qui --> that is what
qui est-ce qui --> who is who

J'espère que ma réponse vous aiderait.
Bonne chance et bonne continuation dans vos études en français, la langue de Molière et qui a été utilisé par le monde français depuis l’époque d’Hugues Capet

"Qu'est-ce que s'est passé?" -- What happend.
"Qui est-ce que tu as rencontré" -- Whom did you meet?

Que = what. The final "e" gets nixed when followed by the "e" of "est".
Qui = who. The final "i" is impervious to the vowel that succeeds it.

-- Chris (not a native speaker).