Which set of ordered pairs (x,y)(x,y) could represent a linear function? \mathbf{A}= A= \,\,\left\{(2, 9),\,\,(4, 5),\,\,(6, 1),\,\,(7, -1)\right\} {(2,9),(4,5),(6,1),(7,−1)} \mathbf{B}= B= \,\,\left\{(-1, -8),\,\,(0, -3),\,\,(1, 3),\,\,(2, 8)\right\} {(−1,−8),(0,−3),(1,3),(2,8)} \mathbf{C}= C= \,\,\left\{(-9, 5),\,\,(-3, 3),\,\,(3, 0),\,\,(9, -2)\right\} {(−9,5),(−3,3),(3,0),(9,−2)} \mathbf{D}= D= \,\,\left\{(1, -8),\,\,(2, -6),\,\,(3, -3),\,\,(4, 0)\right\} {(1,−8),(2,−6),(3,−3),(4,0)}