Let P Q and RS be two 2-bit binary numbers. That is, each of P, Q, R, and S is 0 or 1. Design a circuit that has four inputs, P, Q, R, and S, and one output Z such that the output is 1 if and only if P Q + RS 4. Your answer must include (a) an Input/Output table, (b) a Boolean expression, and (c) a drawing of the circuit corresponding to your Boolean expression.