Which of the following are indications the solution of a linear system may be vulnerable to round off error. The coefficient matrix is not diagonally dominant. The elements of the coefficient matrix span several orders of magnitude. Roundoff error is never a concern if you use Gauss elimination because it is a direct solution method. The solution is very sensitive to small changes in even a single element of the coefficient matrix. The condition number of the coefficient matrix is much larger than one. The solution requires partial pivoting. The determinant of the coefficient matrix is close to zero. The system is overdetermined.