Final answer:
Percy, Tyson, and Annabeth each demonstrate heroic acts throughout the quest, showing bravery, selflessness, loyalty, and intelligence.
Step-by-step explanation:
a) Percy's heroic act: One moment in the quest that Percy acts heroically is when he faces the Minotaur in the very beginning of the story. He manages to defeat the monster and save his friend, Grover, showing bravery and selflessness.
b) Tyson's heroic act: Tyson's heroic act occurs when he sacrifices himself to save Percy and Annabeth from the sea serpent, Charybdis. He willingly puts himself in danger to protect his friends, demonstrating loyalty and courage.
c) Annabeth's heroic act: Annabeth's heroic act takes place when she devises a plan to outsmart the Sphinx, who has been guarding the entrance to the Labyrinth. She uses her intelligence and strategic thinking to solve the Sphinx's riddle, allowing the group to proceed on their quest.
Based on the given information, we can determine that each of these characters has shown heroic qualities at different points in the story.