What might a 'harbinger' foreshadow?

A 'harbinger' is a term that refers to a person or thing that announces or signals the approach of another event or entity. Its primary function is to indicate that something is forthcoming, which aligns perfectly with the notion of foreshadowing the arrival of something or someone. In various contexts, a harbinger can be a sign or an omen, often suggesting that a significant change, event, or development is imminent.

The other options do not capture the essence of what a harbinger signifies. For instance, a sudden change in climate might occur but doesn’t specifically pertain to the signaling aspect of a harbinger. Similarly, a sense of warmth and friendliness relates to emotional states rather than indicating an impending event, and unexpected financial gain does not connect with the concept of something being signaled or foreshadowed by a harbinger. Thus, the choice that connects directly to the notion of anticipation and signaling the approach of something is the most accurate interpretation.