Which formatting option increases the space between lines of text?

Line spacing is the formatting option that specifically increases the space between lines of text. This adjustment allows for greater readability and can create a more visually appealing layout in documents. By setting the line spacing to a certain measurement (such as single, 1.5, or double spacing), users can control how much distance there is between each row of text, which can be particularly important in lengthy documents, academic papers, or any context where clarity is paramount.

While indentation refers to the space added at the beginning of a paragraph to create visual structure, it does not affect the space between the lines themselves. Margins determine the white space around the edges of the page, affecting how much text fits on the page but not the spacing within the text itself. Font style impacts the appearance of characters and typography but does not influence line spacing. Thus, line spacing is the clear and relevant choice for adjusting the vertical space between lines in a document.