What characterizes "zeal"?

"Zeal" is characterized by enthusiasm and intensity, often related to a passionate pursuit of a cause or an objective. The term conveys a sense of fervor and dedication, suggesting that one is not just interested but is actively and energetically involved in whatever activity, belief, or goal they are pursuing. This intensity and eagerness are what set zeal apart from mere interest or engagement. The other options, which relate to indifference or calmness, do not reflect the fervent and proactive nature of zeal, making them inconsistent with the correct understanding of the term.