The Coordinates of Point a Are 300 Units of X

The coordinates of point A are 300 units of X and 40 units of Y.The coordinates of point B are 280 units of X and 30 units of Y.With X on the horizontal axis and Y on the vertical axis,the slope of the line between points A and B is

A) + 0.50
B) + 2.00
C) + 0.33
D) - 2.00
E) - 0.50