We consider the addition of two 2’s compliment numbers $$b_{n - 1}b_{n - 2}.......b_{0}$$ and $$a_{n - 1}a_{n - 2}.........a_0$$. A binary adder for adding two unsigned binary numbers is used to add two binary numbers. The sum is denoted by $$c_{n - 1}c_{n - 2}.......c_{0}$$ The carry out is denoted by $$c_{out}$$. The overflow condition is identified by

A

$$c_{out}(\overline{a_{n - 1} \oplus b_{n - 1}})$$

B

$$\overline{a_{n - 1}}b_{n - 1} \overline{c_{n - 1}} + \overline{a_{n - 1}b_{n - 1}} c_{n - 1}$$

C

$$c_{out} \oplus c_{n - 1}$$

D

$$a_{n - 1} \oplus b_{n - 1} \oplus c_{n - 1}$$