Which of the following is the correct pause-resume signal pair for a stopped process?

• A. SIGKILL and SIGTERM
• B. SIGINT and SIGQUIT
• C. SIGHUP and SIGPIPE
• D. SIGSTOP and SIGCONT

Answer: (D)

Pausing and resuming a process in Unix-like systems is done with signals that control its execution state. To pause a process, you send a stop signal that halts it, and to resume, you send a continue signal that wakes it back up. The stop signal used for this purpose halts unconditionally, and the corresponding continue signal resumes the process regardless of its prior state. This combination is exactly what you’d use to pause a stopped process and then resume it.

Signals that terminate a process (like SIGKILL or SIGTERM) are not about pausing and later continuing; they end the process. Interrupt signals from the terminal (SIGINT, SIGQUIT) are for user-initiated interrupts and have different semantics. Hangup (SIGHUP) and broken pipe (SIGPIPE) signals handle other conditions and aren’t about pausing/resuming. So the pair that fits pause and resume best is the stop signal followed by the continue signal.