This is the 1179th most frequent Turkish word.
sorusuna
"To his/her/its question."
The word "sorusuna" here means "to the question" (dative case) referring to the student's question.
Öğrencinin sorusuna öğretmen dikkatlice cevap verdi.
The teacher carefully answered the student's question.
The word "sorusuna" refers to a specific question mentioned prior, and indicates an indirect object related to the situation (dative case).
Bilim adamları bu sorusuna henüz bir çözüm bulamadı.
Scientists have not yet found a solution to this particular question.
The word "sorusuna" indicates the question being posed to the politicians, focusing on their expected reaction (dative case).