Final answer:
Theseus is willing to sacrifice his life to defeat the Minotaur in the myth, emphasizing the theme of heroism and sacrifice.
Step-by-step explanation:
The answer to the question about what happens to Theseus in the myth to emphasize the theme is option C: Theseus is willing to sacrifice his life to defeat the Minotaur. In the myth of Theseus and the Minotaur, Theseus volunteers to enter the labyrinth and confront the Minotaur in order to save his people from being sacrificed. His bravery and selflessness in facing a dangerous creature highlights the theme of heroism and sacrifice.