Solution

The correct answer is option 4

Key Points

• NAND Gate: The NAND gate gives output 1 when both inputs are 0. The truth table for a NAND gate is:

  Input A	Input B	Output (A NAND B)
  0	0	1
  0	1	1
  1	0	1
  1	1	0

• NOR Gate: The NOR gate does not give output 1 when both inputs are 0. The truth table for a NOR gate is:

  Input A	Input B	Output (A NOR B)
  0	0	1
  0	1	0
  1	0	0
  1	1	0

• XOR Gate: The XOR gate gives output 0 when both inputs are 0. The truth table for an XOR gate is:

  Input A	Input B	Output (A XOR B)
  0	0	0
  0	1	1
  1	0	1
  1	1	0

• XNOR Gate: The XNOR gate gives output 1 when both inputs are 0. The truth table for an XNOR gate is:

  Input A	Input B	Output (A XNOR B)
  0	0	1
  0	1	0
  1	0	0
  1	1	1

Additional Information

• The XOR gate is the only gate that does not give an output of 1 when both inputs are 0, as it specifically outputs 1 only when the inputs are different.
• All other gates (NAND, NOR, and XNOR) produce a 1 output in specific cases when both inputs are 0.

Hence, the correct answer is: option 4) C Only