Q39

We consider the addition of two $2's$ complement numbers $b_{n-1}b_{n-2}\dots b_{0}$ and $a_{n-1}a_{n-2}\dots a_{0}$. A binary adder for adding unsigned binary numbers is used to add the two numbers. The sum is denoted by $c_{n-1}c_{n-2}\dots c_{0}$ and the carry-out by $c_{out}$. Which one of the following options correctly identifies the overflow condition?