"The Lady or the Tiger?" by Francis Richard Stockton is a short story, not a business document with clearly demarcated divisions. Such literary terms as introduction, conflict, climax and resolution are not intended to be precise, but rather are ways critics help readers think through a general structure of action or narrative. Since these terms are taken from Aristotle's account of classical Greek tragedy, they cannot really be applied with any precision to a modern short story.
The central conflict in the story has to do with the choice that the princess must make. She loves the young man and can choose for him to be eaten by the tiger or to be married to a beautiful young woman. The end of the introduction is the moment at which the young man enters the arena. The climax of the story is the moment when the princess indicates which door the young man should choose and the young man opens the door. Since the reader is never told whether the lady or the tiger appears, there is no resolution.