Which one of the following equations is a correct identity for arbitrary 3 × 3 real matrices P, Q and R?

Which one of the following equations is a correct identity for arbitra

1.	Which one of the following equations is a correct identity for arbitrary 3 × 3 real matrices P, Q and R?
A.	P(Q + R) = PQ+ RP
B.	(P - Q)2 = P2 – 2PQ + Q2
C.	det (P +Q) = det P + detQ
D.	(P + Q)2 = P2 + PQ + QP + Q2
Answer» E.