Use Cramer's Rule, If Possible, to Solve the System of Linear

Multiple Choice

Use Cramer's Rule, if possible, to solve the system of linear equations.
- $$\left\{ \begin{array} { l } x + y = 7 \\6 x + 6 y = 42\end{array} \right.$$

A) $( 2,5 )$
B) $( 0,0 )$
C) $\{ ( x , y ) \mid x + y = 7 \}$
D) $\varnothing$