Consider the given insert function for a queue. Which of the following can be replaced with if$($isQueueFull$($c$)$ functionality stays the same?

$\{$

void insert$($struct Queue $*$c$,$ int x$)$

if$($c$->$rear $==$ QUEUE$\_$SIZE$-1)$

c$->$rear$=0$;

else

$($c$->$rear$)++$;

if$($isQueueFull$($c$))$

cout$<<$"Overflow: Queue is full"$<$items$[$c$->$rear$]=$x;

$\}$

a$.$ if $($c$->$rear $==$ QUEUE$\_$SIZE$-1)$

Ob$.$ if $($c$->$rear $!=$ c$->$front$)$

c$.$ if $($c$->$front $==$ c$->$rear$)$

d$.$ if $($c$->$front $==$ QUEUE$\_$SIZE$-1)$