(please help!) The center of a circle is at the origin on a coordinate grid. The vertex of a parabola that opens upward is at (0, 9). If th circle intersects the parabola at the parabola's vertex, which statement must be true?

Several paint mixtures are made by mixing blue paint and white paint. paint colors blue paint white paint mixture a 5 cups 12 cups mixture b 6 cups 6 cups mixture c 4 cups 12 cups mixture d 5 cups 6 cups which mixture has the highest ratio of blue paint to white paint