amen - i agree - i think most people missed the boat here - the answer is that teenagers and adults also
For the one about humans being predisposed to certain intervals, the choice about the infants not hearing the music before the test had to have been wrong to strenghten it.
The question asks to STRENGTHEN why they would all respond more to these intervals and the conclusion of the argument said that many cultures use these intervals in their music. (this in the real world happens to be true, by the way) I put the answer choice about many teens and adults in other studies also responded similarly as the babies did, because this would mean that HUMANS are predisposed to hearing those intervals by the music that they listen to , no matter what culture they are from
(all this from a music major)
Take this s you will
Wrong, the point was that the babies are NATURAL inclined to respond to the music that is common in many cultures. If the infants had been exposed to it previously, the response may not be innate, it may be learned. Thus knowing that the infants had not been exposed to the music before strengthened the argument that they are naturally inclined to respond to said music.