Here, determinant of matrix = 16 and order = n = 3 Determinant formed by replacing each of its elements by its cofactor = determinant of transpose of adjoint = determinant of adjoint of matrix .....(∵ The determinant of a square matrix is the same as the determinant of its transpose.) =( determinant of matrix )n−1 =(16)3−1 =(16)2 =256 Hence, option (3) is correct.