Which of the following calls fail if the requested shared memory segment does not already exist?

$($a$)$ shmget $($key$,$ sizeof $($int$),$ IPC$\_$CREAT$|0777)$;

$($b$)$ shmget $($key$,$ sizeof $($int$),0777)$;

$($c$)$ shmget$($IPC$\_$PRIVATE, sizeof $($int$),0777)$;

$($d$)($b$)$ and $($c$)$

$($e$)$ None of the above

Which of the following is INCORRECT about shared memory?

$($a$)$ An IPC method that does not need kernel intervention to deliver messages

$($b$)$ An IPC method that lacks a mean of synchronization between the communicating pro$-$

cesses

$($c$)$ An IPC method that can be used for communication between process, and between threads

as well

$($d$)$ It is a system resource that can continue to exist even after the processes that are using

it terminate.

$($e$)$ None of the above