Correct Answer: A
Explanation:
Both of these adjectives should go well with joy and verve. Though tuneful, catchy, or popular might work, only the combination of jaunty and insouciant, which means carefree, fits both needs.
Verve: vigor and energy, as in movement, portrayal
Jaunty: in fashion; stylish; chic
Cacophonous: harsh, jarring sound; dissonance