If rectangle ABCD, defined by the coordinates A(0, 0), B(0, -4), C(-2, -4), D(-2, 0), is dilated by a scale factor of 2, with resulting vertex A' at (2, 4), what is the center of the dilation?
A) (0, 0)
B) (2, 4)
C) (0, -4)
D) (-2, -4)