Find the lengths of the sides:
BA = 4, this would be y1
BC = 6, this would be x1
CD = 2, this would be y2
DE = 3, this would be x2
The slope is the Y over X
Slope of ABC = 4 / 6
Slope of CDE = 2 / 3
Answer A equals both of those:
6-2 / 9-3 = 4/6
8-6 = 12-9 = 2/3