When Tobias passed his driver's exam, the song Fire and Rain by James Taylor was playing on the radio. Now, whenever Tobias hears this sad song, he feels joyous. Tobias's joyful reaction to the sad song can be classified as a(n):

conditioned response

Explanation:

Based on the information provided within the question it can be said that Tobias's joyful reaction to the sad song can be classified as a conditioned response. This term refers to an automatic response that has been trained to occur to an specific neutral stimulus. Which in this case since the song was playing during a joyfull moment in Tobias's life then he has associated that song to joy even though it is a sad song.

because he is that the right