Consider the following circuit which one of the following

Consider the following circuit which one of the following gives the function implemented by the MUX based digital circuit?

1. F = C₂ C₁S + C₂C1 ( A + B)
2. F = C₂ C₁ + C₂C₁ + C₂ C₁S + C₂C1 AB
3. F = AB + S
4. F = C₂ C₁+ C2 C₁S + C₂C₁ A B

The given circuit
From figure
F = C₂ C₁.1 + C₂C₁( A + B) + C₂ C₁S + C₂ C₁.0
or
F = C₂ C₁ + C₂ C₁S + C₂C₁ A B