13. (L79) Tell the center and vertices of the ellipse for the equation 25x 2 + 4y 2 = 100. A. center: (0, 0); vertices: (0, -5) and (0, 5) B. center: (1, 1); vertices: (1, -4) and (-1, -1) C. center: (1, 0); vertices: (4, -5) and (0, 0) D. center: (-1, 1); vertices: (0, 0) and (0, 5)