Consider the following circuit with four push button switches namely : S1, S2, S3, and S4. These four switches can either be in pushed or released states which are represented by 1 and 0
respectively. (Note : In the circuit given below, all the switches are in released state having value 0.)
Which of the following Boolean expressions represents the function of the bulb, if the on state of the bulb is represented by the value 1 ?