I think they goofed and gave the wrong translation.
The audio sounded like "kde je to." That's what I typed and it came back green, but the translation they gave was "who is it."
I can hear "Kdo je to".
BTW, the process works differently. We are NOT translating tje English sentenced. We choose the Czech sentence and translate it to English. Duolingo generates the audio automatically.
I see "Who is that" is counted as correct, but how is the difference made with "to" being "it" or "that"? Is it just context? I've seen "Kdo to je?" - does that stress the "to" more to mean "that"?