The matrix P is the inverse of a matrix Q. If I denotes the identity matrix, which one of the following options is correct?

The matrix P is the inverse of a matrix Q. If I denotes the identity m

1.	The matrix P is the inverse of a matrix Q. If I denotes the identity matrix, which one of the following options is correct?
A.	PQ = I but QP ≠ I
B.	QP = I but PQ ≠ I
C.	PQ = I and QP = I
D.	PQ – QP = I
Answer» D. PQ – QP = I