In the following circuit, the output `Y` for all possible inputs `A` and `B` is expressed by the truth table:

Options

A. `{:(A,B,Y),(0,0,0),(0,1,0),(1,0,0),(1,1,1):}`
B. `{:(A,B,Y),(0,0,1),(0,1,1),(1,0,1),(1,1,0):}`
C. `{:(A,B,Y),(0,0,1),(0,1,0),(1,0,0),(1,1,0):}`
D. `{:(A,B,Y),(0,0,0),(0,1,1),(1,0,1),(1,1,1):}`

Answer

D

Explanation

`{:(A,B,Y),(0,0,0),(0,1,1),(1,0,1),(1,1,1):}`
Key idea: gates I and II are NOR gates. We can simplify the gate circuit as
Here gates-I and II are NOR gates the output (`A+B`) of gate-I will be appeared as input of gate-ii. The final output is
`Y=A+B=A+B`
This is the boolean expression of OR gate whose truth table is given below.