The center of a circle is at the onigin on a coordinate grd. The vertex of a parabola that opens upward is at (0, 9). If the circle intersects the parabola at the parabola's vertex, which statement must be true?
O The maximum number of solutions is one.
O The maximum number of solutions is three.
O The circle has a radius equal to 3.
O The circle has a radius less than 9.