Use the augmented matrix to determine if the linear system is consistent. Is the linear system represented by the augmented matrix consistent? A. Yes, because the rightmost column of the augmented matrix is a pivot column. B. Yes, because the rightmost column of the augmented matrix is not a pivot column. C. No, because the rightmost column of the augmented matrix is a pivot column. D. No, because the rightmost column of the augmented matrix is not a pivot column.

If the reduced row echelon form of the coefficient matrix of a linear system of equations in four different variables has a pivot, i.e. 1, in each column, then the reduced row echelon form of the coefficient matrix is say A is an identity matrix, here I₄, since there are 4 variables.

[tex]\left[\begin{array}{cccc}1&0&0&0\\0&1&0&0\\0&0&1&0\\0&0&0&1\end{array}\right][/tex]

Then the corresponding augmented matrix [ A|B] , where the matrix is the representation of the linear system is AX = B, must be:

[tex]\left[\begin{array}{ccccc}1&0&0&0&a\\0&1&0&0&b\\0&0&1&0&c\\0&0&0&1&d\end{array}\right][/tex]

Now the given linear system is consistent as the right most column of the augmented matrix is a linear combination of the columns of A as the reduced row echelon form of A has a pivot in each column.

Thus, the correct option is (A).