The following pair of processes share a common variable $x.$

Process A

int $Y$;

A$1$: $Y=x^{**}2$;

A$2$: $x=Y$;

Process B

int $Z$;

$B1$:$Z=x+1$;

B$2$: $x=Z$;

$x$ is set to $5$ before either process begins execution. As usual, statements within a process are executed sequentially, but statements in process A may execute in any order with respect to statements in process B$.$ How many different values of $x$ are possible after both processes finish executing?

$2.$a

$3*b$

$4.c$

$8.d$