Answer: Es una pena que a tu hermana no la hayan contratado en el ayuntamiento
Step-by-step explanation: I guess that we have the sentence:
"es una pena que a tu hermana no la _______ (contratar) en el ayuntamiento"
And we must complete it with the subjuntive preterite tense, where the verb is "contratar" and we have that the conjugation is:
"ellos/ellas la hayan contratado"
Where the person doing the action here is "El ayuntamiento" or "the City Hall", so we treat this as a plural person, then we should use "hayan" that is the conjugation for plural cases.
then the complete sentence would be:
"Es una pena que a tu hermana no la hayan contratado en el ayuntamiento"