The answer to your question is love.
A is wrong cause summer is capitalized
B is wrong cause Florida isn’t capitalized
C should be correct cause the week day is capitalized, and the movie is too but the period should be a “,”.
D is wrong cause birthday shouldn’t be capitalized
The best answer for this question would be:
The music symbolizes pleasure and relaxation, so it brings a
quietly comfortable, contented mood to the poem.
Music stimulates the emotions of people that listen to it,
when attach to other artstic aspects like poetry it enhances the overall mood.