Solve the System by the Method of Your Choice $$\begin{array} { l } x + y = 5 \\x + y = - 4\end{array}$$

Multiple Choice

Solve the system by the method of your choice. Identify systems with no solution and systems with infinitely many solutions, using set notation to express their solution sets.
- $$\begin{array} { l } x + y = 5 \\x + y = - 4\end{array}$$

A) $\{ ( 0,1 ) \}$
B) $\{ ( 5 , - 4 ) \}$
C) $\{ ( x , y ) \mid x + y = 5 \}$
D) $\varnothing$