On a Coordinate Graph with Y on the Vertical Axis

Multiple Choice

On a coordinate graph with y on the vertical axis and x on the horizontal axis,suppose point A represents co-ordinates (X = 10,Y = 12) and point B represents co-ordinates (X = 5,Y = 7) .The slope of the straight line joining points A and B is

A) -1.
B) 1.
C) 2/3.
D) 3/2.
E) 5/6.