In Part 1 of "Treasure Island," several elements serve as hints or foreshadowing. Each of the examples you've provided contributes to the overarching themes and plot development in the story:
-
The song "Fifteen men on a dead man's chest..." - This song foreshadows themes of piracy, betrayal, and greed, setting a dark tone for the adventure to come.
-
The indulgence in rum that precipitates a character's death - Characters’ reckless behavior, particularly around alcohol, hints at the dangers and moral decline associated with piracy.
-
The presence of Black Dog - Black Dog's unexpected arrival and menacing demeanor foreshadow impending conflict and the treacherous nature of the crew.
Since all these points contribute significantly to the narrative, it can be concluded that your answer is correct: All answers are correct.