Correct Answer is (A)
In operating systems, a spooled device refers to a device (such as a printer) that utilizes a spooling (Simultaneous Peripheral Operations On-line) technique for handling input/output operations.
When a spooled device is used, data to be printed or processed is first stored in a buffer or a spool file on the system's disk or in memory. This allows the system to handle multiple requests concurrently without having to wait for the device to become available. The spooling system then manages the process of transferring data from the spool file to the device, allowing the application to continue its operation without waiting for the device to finish processing.
Spooling helps improve system performance and efficiency by decoupling the device operation from the application, reducing idle time, and enabling multiple tasks to use the same device simultaneously. It is commonly used for printers, where multiple users may submit print jobs simultaneously, and the spooler manages the print queue and schedules jobs for printing.