Which of the following is a common tool for formatting text?

Text alignment is a fundamental tool for formatting text. It determines how text is positioned within a document or a designated space. Common alignment options include left, center, right, and justified. Each alignment style serves different purposes for readability and aesthetic appeal, enabling the text to be visually organized in a way that enhances the overall presentation of the document.

Other choices do relate to document management or editing but do not primarily focus on text formatting. For instance, cell merging is typically associated with adjusting tables or spreadsheets rather than general text formatting. File saving pertains to storing documents, which is essential for preserving work but does not alter the formatting of the text itself. The undo function is a helpful editing tool for reversing recent actions but does not specifically relate to how text is formatted in a document.