"This is you who have chosen."
Translation:C'est vous qui avez choisi.
Months later, now that I look at it again, I realize with chagrin that the French "vous" here can be interpreted in the singular or plural ("you" formal singular, and "you" plural), so on those grounds I agree that "have" is also possible. I have to get into the weeds here though. Regarding your test of omitting the "who", I suspect it isn't valid, because I think the "have" or "has", technically has to agree with "who", not "you". And I would say that the effect of the "who" is to change the 2nd person to the 3rd person in mid-sentence, and it can be awkward. When I test it, personally I find I can say both 1) "You, who have chosen..." and 2) "You, who has chosen...", of course depending on whether I'm speaking to a group or just one person. The first sounds fine because it so happens that "have" is the same form for both 2nd person plural and 3rd person plural, so the switch is sort of disguised. The second sounds strange because "has" is only 3rd person. Maybe correct, but most natives wouldn't be comfortable with it. The other issue here: "This is.." just sounds bizarre to me. Which brought me to "It's" and then made me incorrectly balk at the idea of "It's you who have..." due to the mess of sing. and plural. So: I think in the real world an English speaker would say in most contexts "You're the one who has chosen." or "You're the ones who have chosen".
You're right about "You're the ones who have..." etc., but it's absolutely not correct to see "who" as necessarily a 3rd person pronoun. In prayers (I'm not a religious person, just a Latin teacher, so I read lots of old stuff in various languages) it's common to flatter the deity being addressed as "You who do this and that." When the rel. prn. (who, in Engl.) is coupled with a 2nd pers. verb (and in non-English languages we can tell by the verb ending that it's 2nd pers. and not 3rd), it's really necessary to say "O you who move the sun and the other stars" (or whatever). In other words, "who" doesn't dictate the form "moves," although I've noticed this error frequently in my young students. (There must be King James Bible or Shakespearean "thou who --st" or "ye who --" forms in prayers...)
Yes, Suzanne, I now see you're right--I easily got hits for "thou who dost". This all reminds me of a rather formal structure in German that has always struck me as really strange: "Du, der du tust...." (You, who you do...) in which the "you" is repeated for good measure in the relative clause. I think when the 2nd person -st verb ending fell away in English it made this structure too awkward/confusing to survive.
I'm very uncorfortable with the "correct" answer and even with the english original. IMO once you introduce a sub-sentence with who the subject of this is"the one" (or "the ones") and therefore the verb must be in the third person. So, CORRECT ENGLISH for me is: "It is you who HAS chosen" and CORRECT FRENCH should be "c'est toi qui A choisi" (or "c'est vous qui a choisi"). All this is most definately true in spanish: "Eres tú quien HA elegido" to put "has" instead of "ha" just because i'm talking about "tú" would be a mistake, period.