Answer:
Self-confidence comes from within.
Explanation:
The theme of a story is the moral lesson that the author wants to convey to the readers. It is the main idea of the story, the central idea that can help teach any lesson to the readers.
In the given passage from an interview, Florence Griffith-Joyner revealed: "my self-confidence comes from my faith in God and faith that I have in myself, the belief that my parents instilled in me when I was very young that I could do anything that I wanted to do--anything I set my mind to, and anything that I really believed in." This shows how she 'instilled' the will to do her best, no matter the outcome.
Thus, the theme that the excerpt supports is that self-confidence comes from within a person.