Does control the input/output operation of the process one of the function of a process control block?

Yes, controlling the input/output operations of a process is one of the functions of a process control block. The process control block contains information about the process's input/output devices, such as the status of open files, pending input/output requests, and the location of data in memory or on disk. This information is used by the operating system to manage the process's input/output operations efficiently.