Please explain these questions and provide their correct options:- 45,46,47,48

1.45. A square matrix is a diagonal natit if and only if it is (i) upper triangular Cii) lower triangular (ii) both upper triangular and lower triangular (iv) none of these. 1.46. Let A be a non-singular matrix of order 3. Thén the rank of the matrix A is (I (i) 2 (ii)3 (iv) 9. (0I 0) 147. If A = |0 0 . then rank of the matrix A + A2 + A^ is () 1 (i) 2 (ii) 3 (iv) none of these. 1.48. Let A and B be two real symmetric matrices of order n with index iA ig rank rA Ig and signature sA g respectively. Then A and B are congruent if and only if )iA ig and ra ()ia g and sa dg (ii) ra = "B and sa g (iv) none of these. ringulbr if