The rule of a function changes from

f(x) = x² − 4 to g(x) = -x² + 4 when it is dilated.

Which statement best describes how this dilation affects the graph of f(x)?

A. The graph is reflected across the x-axis.
B. The graph is reflected across the y-axis.
C. The graph moves up 8 units.
D. The graph moves down 8 units.