Which equation shows the substitution method being used to solve the system of linear equations?
X+y=6
X=y+2
A x+(y+2)=6
B (y+2)+y=6
C x=(x-6)+2
D x+y=y+2
X+y=6
X=y+2
A x+(y+2)=6
B (y+2)+y=6
C x=(x-6)+2
D x+y=y+2