Answer : Option (B)
SPOOLing (Simultaneous Peripheral Operations OnLine) is a technique in which an intermediate device such as disk is interposed between process and low speed I/O device like a printer. If a process attempts to print a document but printer is busy printing another document, the process, instead of waiting for printer to become available, write its output to disk. When the printer become available the data on disk is printed. Spooling allows process to request operations from peripheral devices without requiring that the device be ready to service the request.
