What characterizes someone who is "vehement"?

Someone who is described as "vehement" embodies intensity and forcefulness in their expression or actions. This term often applies to individuals who are passionate, assertive, or emotionally charged about a particular opinion or belief. Their strong convictions are typically conveyed through vigorous speech or behavior, drawing attention to their fervent commitment to their ideals.

In contrast, the other options present characteristics that are quite the opposite of "vehement." Indifference suggests a lack of interest or concern, weakness denotes a lack of strength or effectiveness, and shyness indicates a reserved or withdrawn demeanor—all of which do not align with the assertive and passionate nature associated with being vehement. Thus, the choice that highlights intensity and forcefulness accurately captures the essence of the term.