The logic operations performed by the given digital circuit is equivalent to:

• Correct answer
  A

  
  AND
• B

  
  NOR
• C

  
  OR
• D

  
  NAND

Solution

$\begin{aligned} & \mathrm{Y}=\overline{\mathrm{Z}}=(\mathrm{A}+\mathrm{B}) \cdot(\mathrm{A} \cdot \mathrm{B})=\mathrm{A} \cdot \mathrm{A} \cdot \mathrm{B}+\mathrm{AB} \cdot \mathrm{B} \\ & \mathrm{Y}=\mathrm{AB}+\mathrm{AB}=\mathrm{A} \cdot \mathrm{B} \\ & \therefore \text { It is an } \mathrm{AND} \text { Gate. }\end{aligned}$

Hence, the correct answer is option: 'A'.