The two lines are coincident (essentially the same line) so every point on the line is a solution. Normally you would say they have infinitely many solutions.
An example of this would be:
y = 2x + 3
2y = 4x + 6
The statement that matches this situation would be D.
D. The system of equations does not have only one solution (it has infinitely many) because the lines do not intersect at *only* one point.
Step-by-step explanation: