A and B are n×n matrices. Mark each statement True or False. Justify your answer.

a. A row replacement operation does not affect the determinant of a matrix.

b. The determinant of A is the product of the pivots in any echelon form U of A, multiplied by (−1)r, where r is the number of row interchanges made during row reduction from A to U.

c. If the columns of A are linearly dependent, then det A=0. d. det (A+B)=det A+det B.