Use Cramerʹs Rule to Solve the System of Equations $$\begin{array} { r } x + y + z = 9 \\2 x - 3 y + 4 z = 7\end{array}$$

Use Cramerʹs rule to solve the system of equations. If D = 0, use another method to determine the solution set.
- $$\begin{array} { r } x + y + z = 9 \\2 x - 3 y + 4 z = 7\end{array}$$

A) Cramer's rule does not apply since $\mathrm { D } = 0 ; \left\{ \left( \frac { - 7 \mathrm { z } + 34 } { 5 } , \frac { 2 \mathrm { z } - 11 } { 5 } , \mathrm { z } \right\} \right\}$
B) Cramer's rule does not apply since $\mathrm { D } = 0 ; \left\{ \left( \frac { \mathrm { z } + 34 } { 5 } , \frac { 2 \mathrm { z } + 11 } { 5 } , \mathrm { z } \right) \right\}$
C) Cramer's rule does not apply since $\mathrm { D } = 0$ ; $\varnothing$
D) Cramer's rule does not apply since $\mathrm { D } = 0 ; \left\{ \left( \frac { - 7 \mathrm { z } + 34 } { 5 } , \frac { 2 \mathrm { z } + 11 } { 5 } , \mathrm { z } \right) \right\}$