Solve Each System by Using Either the Substitution or the Elimination-By-Addition

Multiple Choice

Solve each system by using either the substitution or the elimination-by-addition method, whichever seems more appropriate. $$\left( \begin{array} { c } 8 x - 8 y = 40 \\- 8 x + 3 y = - 15\end{array} \right)$$

A) ( 0, $-$ 5)
B) ( 5, 0)
C) ( 0, 5)
D) infinitely many solutions
E) no solutions