"Is it a boy?"
Translation:Je to chlapec?
That is little slightly different.
Je to kluk? - you are asking if some unknown person is a boy (or asking if an expected child is a boy) .
Je kluk? - is similar but you are asking about a known person. In English it would be Is HE a boy? Not sure how and when you would use this sentence in either language.
The word tiles that are available to chose are: je jaké hoch ko kdo to osoba— they do not include the word tile chlapec. So when I put the wrong answer “je to osoba”, I was told that the right answer was “je to chlapec.” However, I would not have been able to chose that answer, because I was missing the tile for chlapec. I hope that clarifies the small issue I am reporting.
It seems pretty obvious to me that you should have chosen "hoch". The system can report any of the possible translations, because "hoch", "kluk" and "chlapec" are equivalent. Therefore it can say "chlapec" even though only "hoch" was available. There is nothing we can do about that.