Which of the following signals is sent to a process when the key combination CTRL+C is pressed on the keyboard?

SIGTERM (signal 15) is the default termination signal sent by the kill command without arguments, not generated by CTRL+C.

SIGINT (signal number 2) is the interrupt signal generated by the terminal driver when CTRL+C is pressed. It is sent to the foreground process group and by default causes the process to terminate, though processes can catch and handle it programmatically.

SIGSTOP (signal 19) suspends a process and cannot be caught or ignored; it is sent by CTRL+Z, not CTRL+C.

SIGKILL (signal 9) forcefully kills a process and cannot be caught or handled; it is sent explicitly via kill -9 and is not generated by any keyboard shortcut.