Identify the operation performed by the circuit given below:

$$\text{Outputs of the first three inverter-connected NOR gates: } Y_A = \overline{A + A} = \bar{A}, \quad Y_B = \overline{B + B} = \bar{B}, \quad Y_C = \overline{C + C} = \bar{C}$$

$$\text{Output of the final 3-input NOR gate: } Y = \overline{Y_A + Y_B + Y_C} = \overline{\bar{A} + \bar{B} + \bar{C}}$$

$$\text{Applying De Morgan's laws: } Y = \overline{\overline{A}} \cdot \overline{\overline{B}} \cdot \overline{\overline{C}} = A \cdot B \cdot C \implies \text{AND operation}$$