Out of all the choices there is one way that things are, one way that an identity is. Such a limitation or resolution is at the essence of character. In a final accounting, this is all character in role playing games is. Every aspect of character in role playing games leans towards the resolution of this question. I'm Sumner, and I'm playing this cool game.
All answers are accurate, all are valid, and each one fits one piece of the puzzle.
Take away one and the question is not really answered. Even with all those words there are still questions. I would be, but that character would be in the mode of the actor who just reiterates lines. And yet that is a character, or a sort of character, as much as the person who is only playing the game for the sake of interacting with the modern world as a 17th century vampire or to knock some notches down on the sword. Ergo, a character is many things.