Suppose that when a system of linear equations is graphed, one line completely overlaps the other the other line . Which statement is correct ?

A:the system of equations has one solution because the lines intersect at one point
B: the system of equations has one solution because the lines do not intersect at only one point
C:The systems of equations does not have only one solution because the lines intersect at one point
D: The systems of equations does not have only one solution because the lines do not intersect at only one point