Which word best relates to "fervently"?

The word "fervently" signifies an intense and passionate manner of expressing feelings or enthusiasm. Fervently implies strong emotions and a heartfelt commitment to a cause or belief. For instance, someone who advocates for a charitable cause might do so fervently, showing great passion and zeal.

In this context, "passionately" aligns closely with "fervently" as it also conveys a sense of intense emotion and enthusiasm. It suggests that a person is not merely supportive, but is actively and vigorously involved, often with deep emotional involvement.

The other words, although contrasting in meaning, do not capture this sense of intensity and passion. "Indifferently" suggests a lack of interest or concern, while "calmly" implies composure and an absence of strong emotion. "Slowly" refers to the pace of an action rather than the intensity or feeling behind it. Therefore, "passionately" is the best choice as it fully embodies the essence of fervent expression.