The shortcut Ctrl + Shift + & applies an outline border to the currently selected cell or range of cells. This is a specific type of border formatting available in Excel. The ampersand symbol (&) is typically located on the same key as the number 7 on a standard QWERTY keyboard, making the shortcut effectively Ctrl + Shift + 7. This command is part of a set of formatting shortcuts that allow users to quickly apply common cell styles without using the ribbon menu.

A. Ctrl+Alt+B is not a default shortcut for applying borders in Microsoft Excel. It does not have a standard assigned function for cell formatting.
B. Ctrl+Shift+Alt+B is not a recognized default shortcut in Excel for any formatting function, including applying borders.
D. Ctrl+B is the standard shortcut to apply or remove bold formatting to the contents of the selected cells, not to apply cell borders.

1. Microsoft Corporation. (n.d.). Keyboard shortcuts in Excel. Microsoft Support. Retrieved from https://support.microsoft.com/en-us/office/keyboard-shortcuts-in-excel-1798d9d5-842a-42b8-9c99-9b7213f0040f.

Reference Point: Under the section "Ctrl key combination shortcuts

" the documentation lists Ctrl+Shift+& with the description "Applies the Outline border to the selected cells." It also lists Ctrl+B as "Applies or removes bold formatting."

2. Indiana University. (2023

October 24). Keyboard shortcuts for Microsoft Excel. University Information Technology Services (UITS) Knowledge Base. Retrieved from https://kb.iu.edu/d/aawh.

Reference Point: In the "Formatting" table

the shortcut Ctrl+Shift+& is listed with the function "Apply outline border." The shortcut Ctrl+B is listed for "Apply/remove bold."