The correct answer is: E. 2048 KB.
The amount of memory available to application software in a PC is 2048 KB. This is because the first 640 KB of memory is reserved for the BIOS and the operating system. The remaining 1392 KB is available for application software.
The BIOS is a small program that is stored on a chip on the motherboard. It is responsible for initializing the hardware and loading the operating system. The operating system is a program that manages the resources of the computer, such as the CPU, memory, and storage.
Application software is a program that is designed to perform a specific task, such as word processing, spreadsheets, or games. When you open an application, it loads into memory. The amount of memory that an application uses depends on its size and complexity.
If you have multiple applications open at the same time, they will all share the available memory. If one application uses too much memory, it can cause other applications to slow down or crash.
To prevent this, you can close applications that you are not using. You can also use a program called a “task manager” to see how much memory each application is using. If an application is using too much memory, you can close it from the task manager.
I hope this explanation is helpful. Please let me know if you have any other questions.