Which expression is the dual of (P∧Q)∨(R∧S)(P \land Q) \lor (R \land S)(P∧Q)∨(R∧S)?
(P∨Q)∨(R∨S)(P \lor Q) \lor (R \lor S)(P∨Q)∨(R∨S)
(P∧Q)∨(R∧S)(P \land Q) \lor (R \land S)(P∧Q)∨(R∧S)
(P∧Q)∧(R∧S)(P \land Q) \land (R \land S)(P∧Q)∧(R∧S)
(P∨Q)∧(R∨S)(P \lor Q) \land (R \lor S)(P∨Q)∧(R∨S)