Which keyboard shortcut is typically used to apply bold formatting?

The shortcut commonly associated with applying bold formatting in most word processing applications is Ctrl + B. This key combination sends a command to the software to switch the selected text to bold, allowing for enhanced emphasis and visibility. Using bold formatting is a crucial skill in document creation and editing as it helps draw attention to important information or headings, making the text easier to read and understand.

The other options represent different formatting skills: Ctrl + I applies italics, which gives text a slanted appearance for emphasis; Ctrl + U underlines text, adding a line beneath it for additional emphasis; and Ctrl + D is often used for specific dialog boxes or actions, such as 'font settings' in some applications, but it does not apply bold formatting directly. Knowing these shortcuts can greatly increase efficiency when working with text.