If you are submitting a flash fiction to a publication for consideration, the type of formatting your document should adhere to (unless the publication asks for a different format style) should be:

Question

Choose one • 10 points

Single-spaced

Right-justified

Times New Roman, font size 11

Double-Spaced

First line of new paragraph indented

Left-justified
1.5-spaced

First line of new paragraph indented

Left-justified or centered

It doesn't matter because the story itself will be what the editor is interested in.
Best answer

Answer 1

The best answer for formatting a document for submission would be:

Double-Spaced

First line of new paragraph indented

Left-justified

This format is a common standard for literary submissions, ensuring readability and making it easier for editors to annotate or make notes.