Vertices L(2,−1) and N(6,9) of quadrilateral LMNO are opposite ends of one diagonal, while M(8,3) is a vertex on the second diagonal. If the diagonals meet at the point P(4,4), which of the following are the coordinates of the remaining vertex O that will ensure LMNO is a parallelogram?
(a) (7,6)
(b) (0,3)
(c) (0,5)
(d) (0,−5)