If a(0, 0), b(3, 3), c(9, 3), and d(6, 0) are the vertices of a quadrilateral, do the points form a parallelogram? justify your answer. a. yes, it is a parallelogram because the slope of segment ab equals the slope of segment dc, which equals 1, and ab = dc = square root of 18. b. yes, it is a parallelogram because the slope of segment ab equals the slope of segment dc, which equals −1, and ad = cd = 3 units. c. yes, it is a parallelogram because the midpoint of the diagonals of segment ac and segment bd is (4.4, 1.5). d. no, it is not a parallelogram because the slope of segment ab = 1 and the slope of segment dc = −1.