Does the word "qual" not exist? "Quale" looks as though it should be feminine.
"Quale" is genderless. [The next segment is wrong, see Erkte's response below] Sometimes you can cut the final e as in "Qual'è ..." ("Which is ...") but that's still the same word.
"Qual è": no apostrophe there, because it's not elision but truncation. I know because I keep getting it wrong all the time :D
Thank you very much for correcting me, I completely forgot it (to the point that it almost sounds foreign to me now that you mention it), looks like I've got a lot of brushing up to do!
It is indeed genderless both for the singular and plural (quale (m/f sing) -> quali (m/f plur.)).
Because men is plural and would take "are" instead of "is". You could say either, "Which man is forty?" or "Which men are forty?"
If you want the word "is" as translation for "ha" in this phrase you have to offer it in the choices available. Also you are contradicting yourselves viz a viz an earlirer exercise where you have marked the opposite to here. Be consistent.