If you have a $4$ bit adder that adds $4$ bits of $B$ and $4$ bits of A and $1$ bit of Cary in giving $1$ Sum bit and $1$ Carry out bit, What modifications would you have to make to the $4$ bit

adder to enable it to subtract B from A instead? Select all correct choices:

Invert all four bits of B

Set the Carry in equal to $0$

Set the Carry in equal to $1$

Ignore the Carry out

Invert all four bits of A