Use Cramer's Rule to Solve the System of Equations $$\begin{array} { l } x + y = 6 \\3 x + 3 y = 18\end{array}$$

Multiple Choice

Use Cramer's rule to solve the system of equations. If D = 0, use another method to determine the solution set.
- $$\begin{array} { l } x + y = 6 \\3 x + 3 y = 18\end{array}$$

A) Cramer's rule does not apply since $D = 0 ; \varnothing$
B) Cramer's rule does not apply since $D = 0 ; \{ ( 6 - y , y ) \}$
C) $\{ ( 2,4 ) \}$
D) $\{ ( 0,0 ) \}$