For this case we can translate the sentence as:
I like flamenco music. It serves ________ listen.
We must complete the sentence with the most appropriate connector. We have the following options:
-By
-For what
-Why
-To
It is observed that the most appropriate option to complete the sentence is "to".
Finally we have:
I like flamenco music. It serves to listen.
Answer:
Me gusta la música flamenca. Sirve para escuchar.
