On a coordinate plane, a curved line with a minimum value of (0, negative 9) and maximum values of (negative 2.3, 16) and (2.3, 16), crosses the x-axis at (negative 3, 0), (negative 1, 0), (1, 0), and (3, 0), and crosses the y-axis at (0, negative 9). Which is a y-intercept of the graphed function?