What does "mirth" refer to?

Mirth refers to a state of gladness and gaiety, often characterized by laughter and joy. It embodies a sense of happiness and lightheartedness that can be contagious, making it a term often associated with cheerful and festive occasions. When people experience mirth, they typically exhibit expressions of joy, such as laughing, which contributes to a vibrant and uplifting atmosphere. This definition aligns perfectly with the notion of mirth as a celebratory and positive emotional state, which is why this answer is correct.

In contrast, the other options present emotions or attitudes that are quite the opposite of mirth. A solemn attitude denotes seriousness, sadness conveys a feeling of unhappiness, and indifference suggests a lack of interest or concern, all of which fail to capture the essence of joy that mirth represents.