How does the "Mail Merge" feature in Word assist users?

The "Mail Merge" feature in Word is specifically designed to help users create personalized correspondence, such as letters or labels, by merging data from a data source, like an Excel spreadsheet, with a template document. This functionality streamlines the process of generating multiple customized documents at once, allowing users to efficiently produce individualized materials tailored to specific recipients without needing to manually edit each document.

For example, if a user needs to send out a hundred letters to different clients, mail merge enables them to insert the names and addresses from the data source directly into a standard letter format. This automation not only saves time but also minimizes errors that could occur if edits were made manually. Thus, option B accurately captures the primary purpose and utility of the Mail Merge feature in Word.