(A) Ctrl+K
(B) Ctrl+S
(C) Ctrl+C
(D) Ctrl+D
🧠 Explanation:
- Ctrl+S is the universal shortcut key used to save a document in most computer applications.
- This shortcut helps quickly store changes without using the mouse or menu bar.
- It works across various programs like Microsoft Word, Excel, Notepad, and others.
- Option (B) is correct because Ctrl+S specifically performs the save function.