The correct citation for the novel The Great Gatsby by F. Scott Fitzgerald, published in 1925 by Scribner, in MLA format would be:
Fitzgerald, F. Scott. The Great Gatsby. New York, Scribner, 1925.
However, from the options provided, the closest to a correct format with slight modifications would be:
Fitzgerald, F. Scott. The Great Gatsby. New York City, Scribner, 1925.
So, option 3: Fitzgerald, F. Scott. The Great Gatsby. New York City, Scribner, 1925. is the correct choice, noting that "New York" is the standard format in citations.