Which of the following describes the commutative property?
P∧Q≡Q∧PP \land Q \equiv Q \land PP∧Q≡Q∧P
P∨Q≡Q∨PP \lor Q \equiv Q \lor PP∨Q≡Q∨P
P∧(Q∧R)≡(P∧Q)∧RP \land (Q \land R) \equiv (P \land Q) \land RP∧(Q∧R)≡(P∧Q)∧R
P→Q≡Q→PP \rightarrow Q \equiv Q \rightarrow PP→Q≡Q→P