Which statement is true for the given circuit:

1. (a) is OR gate and (b) is NOT gate.
2. (a) is NOT gate and (b) is OR gate.
3. (a) is AND gate and (b) is OR gate.
4. (a) is OR gate and (b) is AND gate.

A NAND gate connected as given in the figure,

The circuit operates like a:

1. NOT gate
2. OR gate
3. AND gate
4. None of these