DOS (Disk Operating System) is a single-tasking system, capable of running only one program at a time.

Grid-lines are the intersecting horizontal and vertical lines on a spreadsheet that define the structure of cells.

Pressing Backspace removes characters to the left of (before) the cursor in a text field.

The OS manages hardware and software resources for system operation.

The operating system is built directly on the computer hardware, functioning as the core management layer.

** The horizontal split bar appears at the top of the vertical scroll bar in MS Word, and allows you to split the window into separate panes to view different parts of your document at the same time.

The correct answer is **A) winword.exe**. When you launch Microsoft Word on a Windows operating system, the executable file that is initiated is named `winword.exe`. This file contains the core program code for Microsoft Word, and running it is what loads the application, its interface, and its functionalities. While other options might seem plausible, `winword.exe` is the specific system name for the Word executable. `word.exe` and `msword.exe` are not the standard executable names for Microsoft Word. `word2003.exe` is too specific to a particular version and even then, it's not the conventionally recognized executable name; newer versions of Word would have their own specific executable names, but the underlying convention points to `winword.exe` as the primary starter.

System files necessary for startup are placed in the boot area of a disk to ensure quick access during the boot process.

RAM allows the system to access any memory cell instantly, independent of location.

GUI refers to a user interface featuring windows, icons, and menus interactable by mouse and keyboard.