Write the System of Linear Equations Represented by the Augmented $\left[ \begin{array} { r r r r | r } 1 & 1 & - 1 & 1 & - 6 \\ 0 & 1 & - 4 & 8 & 0 \\ 0 & 0 & 1 & 4 & 13 \\ 0 & 0 & 0 & 1 & - 3 \end{array} \right]$

Write the system of linear equations represented by the augmented matrix. Use x, y, z, and, if necessary, w for the
variables. Then use back-substitution to find the solution.
- $\left[ \begin{array} { r r r r | r } 1 & 1 & - 1 & 1 & - 6 \\ 0 & 1 & - 4 & 8 & 0 \\ 0 & 0 & 1 & 4 & 13 \\ 0 & 0 & 0 & 1 & - 3 \end{array} \right]$

A) $\{ ( - 102,124,25 , - 3 ) \}$
B) $\{ ( - 6,0,13 , - 3 ) \}$
C) $\{ ( - 8 , - 5,8 , - 4 ) \}$
D) $\{ ( - 3,25,124 , - 102 ) \}$