If a matrix A = [A11 A12 A1n A21 A2n An1 An2 Ann], order(nxn) Aii = 1, Aij = 0 for i j. Then that matrix is known as ________

If a matrix A = [A11 A12 A1n A21 A2n An1 An2 Ann], order(nxn)

1.	If a matrix A = [A11 A12 A1n A21 A2n An1 An2 Ann], order(nxn) Aii = 1, Aij = 0 for i j. Then that matrix is known as ________
A.	Identity matrix
B.	Null matrix
C.	Singular matrix
D.	None of the mentioned
Answer» B. Null matrix