Point O, Point A, and Point B are all on the same line.
That means that if you find the slope from point O to point A, or point A to point B, or point O to point B, they will all have the same slope.
That eliminates answer choices C and D.
Point A (4,2)
Point B (6,3)

Your final answer is
A.
It is 1/2 throughout the line