Given the circuit below, if $M=1,A=0000$ and $B=0000,$ then $S$ is

a$.$ The $2\text{'}$s complement of $B$

b$.$ The I $\text{'}$s complement of $B$

c$.$ None

d$.$ The $2\text{'}$s complement of A

e$.$ The I$\text{'}$s complement of $A$

Clear my choice

converts binary coded information into unique outputs such as decimal, octal digits,