Answer:
Cara using the pretest/postest design.
Explanation:
In this design, she has her participants assess their mood in their pretest context. This means, participants rate their mood before listening to the music genres that Cara has assigned for each one of them.
After that, participants undergo the test by listening to their selected genre, and finally, they rate their mood after that. This is the postest stage of the design, and the answers of this moment will allow Cara to draw comparisons with the pretest results. This comparison is the information that will either confirm Cara's hypothesis or reject it.
