The graph of f (x) = x^2 was transformed to create the graph of g (x) = f (x) - 9.
Which statement about the graph is true?

A. The graph of g is a reflection of the graph of f across the x-axis.

B. The vertex of the graph g is a 9 unit to the right of the vertex of the graph f.

C. The graph of g is a reflection of the graph of f across the y-axis.

D. The y-intercept of the graph of g is 9 units below the y-intercept of the graph of f.