Consider the following code:

module

binary adder $(x,y,A,B,z)$;

output $[3$: $0]x$;

output y;

input $[3$: $0]$ A$,B$;

input $z$;

assign$\{y,x\}=A+B+z$;

endmodule

This code represents

a$.4$ bit adder with errors

b$.4$ bit adder with no errors

c$.$ Cannot be detrmined

d$.8$ bit adder with errors

e$.8$ bit adder with no errors