Select the option that can be used as a one-word substitute for the given phrase.
A short interesting story about a real person or event

To find the correct one-word substitute for the phrase "A short interesting story about a real person or event", let us analyze the meaning of each provided option:

1. Anecdote: A short, amusing, or interesting story about a real incident or person.
2. Sketch: A brief written or spoken description or outline of someone or something, or a rough drawing.
3. Poem: A piece of writing in which the expression of feelings and ideas is given intensity by particular attention to diction, rhythm, and imagery.
4. Narrative: A spoken or written account of connected events; a story (which can be long, short, fictional, or non-fictional).

Based on these definitions, an Anecdote is the precise one-word substitute for a short, interesting story about a real person or event.

Therefore, the correct option is Anecdote.