Final answer:
The keyboard shortcut that moves the cursor backwards one character at a time is Ctrl + B. This command is used in many text editors, but shortcuts can vary between different software applications.
Step-by-step explanation:
You asked which keyboard shortcut moves the cursor backwards one character at a time. The correct answer is b. Ctrl + B.
In many text editors and word processors, pressing Ctrl + B will move the cursor back one character, allowing for precise text navigation. However, it's worth noting that keyboard shortcuts can sometimes vary between different software applications, and in some cases, this shortcut may not have the same functionality or could be reconfigured.
Shortcuts like Ctrl + A (select all text), Ctrl + E (move to the end of a line), and Ctrl + S (save the current document) serve entirely different purposes.