Which statement correctly describes the strongest classification for quadrilateral ABCD with vertices A(-3, 1), B(1, 3), C(2, 1), and D(-2, -1)? A. Quadrilateral ABCD is a rectangle because adjacent sides have slopes that are negative reciprocals. B. Quadrilateral ABCD is a parallelogram because adjacent sides have slopes that are negative reciprocals. C. Quadrilateral ABCD is a rectangle because adjacent sides have slopes that are not negative reciprocals. D. Quadrilateral ABCD is a parallelogram because adjacent sides have slopes that are not negative reciprocals.