Whose prophecies were infamously unacknowledged by others?

Cassandra is the figure whose prophecies were infamously unacknowledged by others. In Greek mythology, she was a daughter of Priam, the king of Troy, and was granted the gift of prophecy by the god Apollo. However, after rejecting Apollo's advances, he cursed her to ensure that no one would believe her predictions, no matter how accurate they were. This tragic aspect of her story underscores themes of fate, the intersection of divine power, and human disbelief.

The other options refer to different figures in mythology, but they do not embody this particular theme of unheeded prophecies as strikingly as Cassandra does. Delphi is famous for its oracle and prophecies that were typically acknowledged or sought after; Hecuba, the wife of Priam, has her own narratives but does not specifically deal with unacknowledged prophecies; and Electra is known for her story of revenge regarding her family rather than for any prophetic abilities. Thus, the narrative surrounding Cassandra distinctly emphasizes her tragic gift of foresight that was rendered useless due to the disbelief of those around her.