Which word indicates a strong supporter or fan?

The word "ardent" perfectly captures the essence of a strong supporter or fan because it conveys a sense of passion, enthusiasm, and fervent dedication toward a particular person, group, or cause. When someone is described as ardent, it implies they possess an intense emotional involvement and a zealous commitment, characteristics often associated with devoted fans who support their interests with great energy and loyalty.

In contrast, the other options suggest a lack of interest or commitment, which does not align with the idea of a strong supporter. "Indifferent" denotes a lack of interest or concern, "apathetic" suggests a disinterest or lack of emotional investment, and "disinterested" refers to being impartial or lacking a personal stake in an issue. These contrasting meanings highlight why "ardent" is the most accurate choice to describe someone who is a strong supporter or fan.