using the coordinates of the 2 dots on line E we can calculate the slope.
the 2 dots are located at (2,4) and (6,2)
the slope is the change in Y divided by the change in X
the change in Y = 2-4 = -2
the change in X = 6-2 = 4
the slope = -2/4 which reduces to -1/2
the answer is A.